645146621 has 16 divisors (see below), whose sum is σ = 743424000. Its totient is φ = 548417520.

The previous prime is 645146599. The next prime is 645146647. The reversal of 645146621 is 126641546.

It is not a de Polignac number, because 645146621 - 2²² = 640952317 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645146681) 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, 666680 + ... + 667646.

It is an arithmetic number, because the mean of its divisors is an integer number (46464000).

Almost surely, 2^645146621 is an apocalyptic number.

It is an amenable number.

645146621 is a deficient number, since it is larger than the sum of its proper divisors (98277379).

645146621 is a wasteful number, since it uses less digits than its factorization.

645146621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1664.

The product of its digits is 34560, while the sum is 35.

The square root of 645146621 is about 25399.7366324929. The cubic root of 645146621 is about 864.0777237214.

The spelling of 645146621 in words is "six hundred forty-five million, one hundred forty-six thousand, six hundred twenty-one".