642133440 has 224 divisors, whose sum is σ = 2439984960. Its totient is φ = 158035968.

The previous prime is 642133439. The next prime is 642133441. The reversal of 642133440 is 44331246.

642133440 is a `hidden beast` number, since 6 + 4 + 213 + 3 + 440 = 666.

It is an interprime number because it is at equal distance from previous prime (642133439) and next prime (642133441).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642133441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 109462 + ... + 115178.

It is an arithmetic number, because the mean of its divisors is an integer number (10892790).

Almost surely, 2^642133440 is an apocalyptic number.

642133440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642133440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1219992480).

642133440 is an abundant number, since it is smaller than the sum of its proper divisors (1797851520).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

642133440 is a wasteful number, since it uses less digits than its factorization.

642133440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5756 (or 5740 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

The square root of 642133440 is about 25340.3520101833. The cubic root of 642133440 is about 862.7303883594.

Adding to 642133440 its reverse (44331246), we get a palindrome (686464686).

The spelling of 642133440 in words is "six hundred forty-two million, one hundred thirty-three thousand, four hundred forty".