261556553476 has 9 divisors (see below), whose sum is σ = 457725758581. Its totient is φ = 130777765312.

The previous prime is 261556553473. The next prime is 261556553501. The reversal of 261556553476 is 674355655162.

The square root of 261556553476 is 511426.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 250610372100 + 10946181376 = 500610^2 + 104624^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261556553473) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 894996 + ... + 1150708.

Almost surely, 2^261556553476 is an apocalyptic number.

261556553476 is the 511426-th square number.

It is an amenable number.

261556553476 is a deficient number, since it is larger than the sum of its proper divisors (196169205105).

261556553476 is an frugal number, since it uses more digits than its factorization.

261556553476 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 511430 (or 255715 counting only the distinct ones).

The product of its digits is 22680000, while the sum is 55.

The spelling of 261556553476 in words is "two hundred sixty-one billion, five hundred fifty-six million, five hundred fifty-three thousand, four hundred seventy-six".