551661506 has 24 divisors (see below), whose sum is σ = 911311212. Its totient is φ = 250272000.

The previous prime is 551661497. The next prime is 551661521. The reversal of 551661506 is 605166155.

It can be written as a sum of positive squares in 2 ways, for example, as 551545225 + 116281 = 23485^2 + 341^2 .

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 143546 + ... + 147338.

Almost surely, 2^551661506 is an apocalyptic number.

551661506 is a deficient number, since it is larger than the sum of its proper divisors (359649706).

551661506 is a wasteful number, since it uses less digits than its factorization.

551661506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4418 (or 4407 counting only the distinct ones).

The product of its (nonzero) digits is 27000, while the sum is 35.

The square root of 551661506 is about 23487.4755135583. The cubic root of 551661506 is about 820.1454758752.

The spelling of 551661506 in words is "five hundred fifty-one million, six hundred sixty-one thousand, five hundred six".