644101465 has 32 divisors (see below), whose sum is σ = 894136320. Its totient is φ = 436311744.

The previous prime is 644101433. The next prime is 644101481. The reversal of 644101465 is 564101446.

It is a cyclic number.

It is not a de Polignac number, because 644101465 - 2⁵ = 644101433 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1537026 + ... + 1537444.

It is an arithmetic number, because the mean of its divisors is an integer number (27941760).

Almost surely, 2^644101465 is an apocalyptic number.

It is an amenable number.

644101465 is a deficient number, since it is larger than the sum of its proper divisors (250034855).

644101465 is a wasteful number, since it uses less digits than its factorization.

644101465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 861.

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 644101465 is about 25379.1541427211. The cubic root of 644101465 is about 863.6108613018.

The spelling of 644101465 in words is "six hundred forty-four million, one hundred one thousand, four hundred sixty-five".