645941974 has 16 divisors (see below), whose sum is σ = 1023986880. Its totient is φ = 304749000.

The previous prime is 645941929. The next prime is 645941981. The reversal of 645941974 is 479149546.

It is a congruent number.

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, 24324 + ... + 43399.

It is an arithmetic number, because the mean of its divisors is an integer number (63999180).

Almost surely, 2^645941974 is an apocalyptic number.

645941974 is a deficient number, since it is larger than the sum of its proper divisors (378044906).

645941974 is a wasteful number, since it uses less digits than its factorization.

645941974 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67995.

The product of its digits is 1088640, while the sum is 49.

The square root of 645941974 is about 25415.3885274257. The cubic root of 645941974 is about 864.4326634939.

The spelling of 645941974 in words is "six hundred forty-five million, nine hundred forty-one thousand, nine hundred seventy-four".