645976054 has 4 divisors (see below), whose sum is σ = 968964084. Its totient is φ = 322988026.

The previous prime is 645976049. The next prime is 645976061. The reversal of 645976054 is 450679546.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 645975995 and 645976013.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161494012 + ... + 161494015.

It is an arithmetic number, because the mean of its divisors is an integer number (242241021).

Almost surely, 2^645976054 is an apocalyptic number.

645976054 is a deficient number, since it is larger than the sum of its proper divisors (322988030).

645976054 is a wasteful number, since it uses less digits than its factorization.

645976054 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322988029.

The product of its (nonzero) digits is 907200, while the sum is 46.

The square root of 645976054 is about 25416.0589785277. The cubic root of 645976054 is about 864.4478657609.

The spelling of 645976054 in words is "six hundred forty-five million, nine hundred seventy-six thousand, fifty-four".