644076453 has 4 divisors (see below), whose sum is σ = 858768608. Its totient is φ = 429384300.

The previous prime is 644076449. The next prime is 644076527. The reversal of 644076453 is 354670446.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 644076453 - 2² = 644076449 is a prime.

It is a super-2 number, since 2×644076453² = 829668954618122418, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644076413) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107346073 + ... + 107346078.

It is an arithmetic number, because the mean of its divisors is an integer number (214692152).

Almost surely, 2^644076453 is an apocalyptic number.

It is an amenable number.

644076453 is a deficient number, since it is larger than the sum of its proper divisors (214692155).

644076453 is a wasteful number, since it uses less digits than its factorization.

644076453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214692154.

The product of its (nonzero) digits is 241920, while the sum is 39.

The square root of 644076453 is about 25378.6613713174. The cubic root of 644076453 is about 863.5996824656.

The spelling of 644076453 in words is "six hundred forty-four million, seventy-six thousand, four hundred fifty-three".