642240380 has 48 divisors (see below), whose sum is σ = 1398841920. Its totient is φ = 247392768.

The previous prime is 642240377. The next prime is 642240407. The reversal of 642240380 is 83042246.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 263849 + ... + 266271.

It is an arithmetic number, because the mean of its divisors is an integer number (29142540).

Almost surely, 2^642240380 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642240380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (699420960).

642240380 is an abundant number, since it is smaller than the sum of its proper divisors (756601540).

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

642240380 is a wasteful number, since it uses less digits than its factorization.

642240380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2918 (or 2916 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 29.

The square root of 642240380 is about 25342.4619956310. The cubic root of 642240380 is about 862.7782783361.

The spelling of 642240380 in words is "six hundred forty-two million, two hundred forty thousand, three hundred eighty".