645113554 has 4 divisors (see below), whose sum is σ = 967670334. Its totient is φ = 322556776.

The previous prime is 645113551. The next prime is 645113633. The reversal of 645113554 is 455311546.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 455311546 = 2 ⋅227655773.

It can be written as a sum of positive squares in only one way, i.e., 612315025 + 32798529 = 24745^2 + 5727^2 .

It is not an unprimeable number, because it can be changed into a prime (645113551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161278387 + ... + 161278390.

Almost surely, 2^645113554 is an apocalyptic number.

645113554 is a deficient number, since it is larger than the sum of its proper divisors (322556780).

645113554 is a wasteful number, since it uses less digits than its factorization.

645113554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322556779.

The product of its digits is 36000, while the sum is 34.

The square root of 645113554 is about 25399.0856922055. The cubic root of 645113554 is about 864.0629606968.

The spelling of 645113554 in words is "six hundred forty-five million, one hundred thirteen thousand, five hundred fifty-four".