621000644 has 24 divisors (see below), whose sum is σ = 1237094208. Its totient is φ = 269999840.

The previous prime is 621000623. The next prime is 621000661. The reversal of 621000644 is 446000126.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (23).

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, 305807 + ... + 307830.

It is an arithmetic number, because the mean of its divisors is an integer number (51545592).

Almost surely, 2^621000644 is an apocalyptic number.

It is an amenable number.

621000644 is a deficient number, since it is larger than the sum of its proper divisors (616093564).

621000644 is a wasteful number, since it uses less digits than its factorization.

621000644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 613675 (or 613673 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 621000644 is about 24919.8845101658. The cubic root of 621000644 is about 853.1603888749.

The spelling of 621000644 in words is "six hundred twenty-one million, six hundred forty-four", and thus it is an aban number.