642257280 has 384 divisors, whose sum is σ = 2686582080. Its totient is φ = 138018816.

The previous prime is 642257219. The next prime is 642257353. The reversal of 642257280 is 82752246.

642257280 is a `hidden beast` number, since 6 + 4 + 2 + 2 + 572 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 684972 + ... + 685908.

Almost surely, 2^642257280 is an apocalyptic number.

642257280 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 642257280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1343291040).

642257280 is an abundant number, since it is smaller than the sum of its proper divisors (2044324800).

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

642257280 is a wasteful number, since it uses less digits than its factorization.

642257280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 986 (or 971 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The square root of 642257280 is about 25342.7954259194. The cubic root of 642257280 is about 862.7858460244.

The spelling of 642257280 in words is "six hundred forty-two million, two hundred fifty-seven thousand, two hundred eighty".