645210137 has 16 divisors (see below), whose sum is σ = 761445888. Its totient is φ = 538980480.

The previous prime is 645210133. The next prime is 645210149. The reversal of 645210137 is 731012546.

It is a cyclic number.

It is not a de Polignac number, because 645210137 - 2² = 645210133 is a prime.

It is a super-2 number, since 2×645210137² = 832592241775117538, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645210133) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21773 + ... + 42005.

It is an arithmetic number, because the mean of its divisors is an integer number (47590368).

Almost surely, 2^645210137 is an apocalyptic number.

It is an amenable number.

645210137 is a deficient number, since it is larger than the sum of its proper divisors (116235751).

645210137 is a wasteful number, since it uses less digits than its factorization.

645210137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20480.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 645210137 is about 25400.9869296451. The cubic root of 645210137 is about 864.1060795286.

The spelling of 645210137 in words is "six hundred forty-five million, two hundred ten thousand, one hundred thirty-seven".