645621706 has 8 divisors (see below), whose sum is σ = 970130304. Its totient is φ = 322244940.

The previous prime is 645621689. The next prime is 645621763. The reversal of 645621706 is 607126546.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 281530 + ... + 283813.

It is an arithmetic number, because the mean of its divisors is an integer number (121266288).

Almost surely, 2^645621706 is an apocalyptic number.

645621706 is a deficient number, since it is larger than the sum of its proper divisors (324508598).

645621706 is a wasteful number, since it uses less digits than its factorization.

645621706 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 565916.

The product of its (nonzero) digits is 60480, while the sum is 37.

The square root of 645621706 is about 25409.0870752965. The cubic root of 645621706 is about 864.2897735236.

The spelling of 645621706 in words is "six hundred forty-five million, six hundred twenty-one thousand, seven hundred six".