642977280 has 480 divisors, whose sum is σ = 2527873920. Its totient is φ = 149667840.

The previous prime is 642977267. The next prime is 642977303. The reversal of 642977280 is 82779246.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 10897891 + ... + 10897949.

It is an arithmetic number, because the mean of its divisors is an integer number (5266404).

Almost surely, 2^642977280 is an apocalyptic number.

642977280 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 642977280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1263936960).

642977280 is an abundant number, since it is smaller than the sum of its proper divisors (1884896640).

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

642977280 is a wasteful number, since it uses less digits than its factorization.

642977280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142 (or 123 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The square root of 642977280 is about 25356.9966675866. The cubic root of 642977280 is about 863.1081331823.

The spelling of 642977280 in words is "six hundred forty-two million, nine hundred seventy-seven thousand, two hundred eighty".