642520670 has 16 divisors (see below), whose sum is σ = 1261677168. Its totient is φ = 233643840.

The previous prime is 642520657. The next prime is 642520673. The reversal of 642520670 is 76025246.

It is a super-2 number, since 2×642520670² = 825665622754497800, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642520673) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2920439 + ... + 2920658.

It is an arithmetic number, because the mean of its divisors is an integer number (78854823).

Almost surely, 2^642520670 is an apocalyptic number.

642520670 is a deficient number, since it is larger than the sum of its proper divisors (619156498).

642520670 is a wasteful number, since it uses less digits than its factorization.

642520670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5841115.

The product of its (nonzero) digits is 20160, while the sum is 32.

The square root of 642520670 is about 25347.9914391654. The cubic root of 642520670 is about 862.9037728601.

The spelling of 642520670 in words is "six hundred forty-two million, five hundred twenty thousand, six hundred seventy".