645739051 has 2 divisors, whose sum is σ = 645739052. Its totient is φ = 645739050.

The previous prime is 645739049. The next prime is 645739079. The reversal of 645739051 is 150937546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645739051 - 2¹ = 645739049 is a prime.

Together with 645739049, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 645738995 and 645739013.

It is not a weakly prime, because it can be changed into another prime (645739091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322869525 + 322869526.

It is an arithmetic number, because the mean of its divisors is an integer number (322869526).

Almost surely, 2^645739051 is an apocalyptic number.

645739051 is a deficient number, since it is larger than the sum of its proper divisors (1).

645739051 is an equidigital number, since it uses as much as digits as its factorization.

645739051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 113400, while the sum is 40.

The square root of 645739051 is about 25411.3960852213. The cubic root of 645739051 is about 864.3421333594.

The spelling of 645739051 in words is "six hundred forty-five million, seven hundred thirty-nine thousand, fifty-one".