645874842 has 16 divisors (see below), whose sum is σ = 1296519552. Its totient is φ = 214496640.

The previous prime is 645874819. The next prime is 645874871. The reversal of 645874842 is 248478546.

It is a junction number, because it is equal to n+sod(n) for n = 645874791 and 645874800.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 196983 + ... + 200234.

It is an arithmetic number, because the mean of its divisors is an integer number (81032472).

Almost surely, 2^645874842 is an apocalyptic number.

645874842 is an abundant number, since it is smaller than the sum of its proper divisors (650644710).

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

645874842 is a wasteful number, since it uses less digits than its factorization.

645874842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397493.

The product of its digits is 1720320, while the sum is 48.

The square root of 645874842 is about 25414.0677971867. The cubic root of 645874842 is about 864.4027159618.

The spelling of 645874842 in words is "six hundred forty-five million, eight hundred seventy-four thousand, eight hundred forty-two".