642408780 has 48 divisors (see below), whose sum is σ = 1937111904. Its totient is φ = 158131200.

The previous prime is 642408773. The next prime is 642408821. The reversal of 642408780 is 87804246.

It is a Harshad number since it is a multiple of its sum of digits (39).

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, 411021 + ... + 412580.

It is an arithmetic number, because the mean of its divisors is an integer number (40356498).

Almost surely, 2^642408780 is an apocalyptic number.

642408780 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

642408780 is an abundant number, since it is smaller than the sum of its proper divisors (1294703124).

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

642408780 is a wasteful number, since it uses less digits than its factorization.

642408780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 823626 (or 823624 counting only the distinct ones).

The product of its (nonzero) digits is 86016, while the sum is 39.

The square root of 642408780 is about 25345.7842648437. The cubic root of 642408780 is about 862.8536806152.

The spelling of 642408780 in words is "six hundred forty-two million, four hundred eight thousand, seven hundred eighty".