645622704554 has 4 divisors (see below), whose sum is σ = 968434056834. Its totient is φ = 322811352276.

The previous prime is 645622704527. The next prime is 645622704563. The reversal of 645622704554 is 455407226546.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 455407226546 = 2 ⋅227703613273.

It can be written as a sum of positive squares in only one way, i.e., 422730131329 + 222892573225 = 650177^2 + 472115^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161405676137 + ... + 161405676140.

Almost surely, 2^645622704554 is an apocalyptic number.

645622704554 is a deficient number, since it is larger than the sum of its proper divisors (322811352280).

645622704554 is a wasteful number, since it uses less digits than its factorization.

645622704554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322811352279.

The product of its (nonzero) digits is 8064000, while the sum is 50.

The spelling of 645622704554 in words is "six hundred forty-five billion, six hundred twenty-two million, seven hundred four thousand, five hundred fifty-four".