5257661661 has 24 divisors (see below), whose sum is σ = 8683356864. Its totient is φ = 3002978880.

The previous prime is 5257661603. The next prime is 5257661663. The reversal of 5257661661 is 1661667525.

5257661661 is a `hidden beast` number, since 5 + 2 + 576 + 6 + 16 + 61 = 666.

It is not a de Polignac number, because 5257661661 - 2¹³ = 5257653469 is a prime.

It is a super-2 number, since 2×5257661661² = 55286012283098557842, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5257661663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 125410 + ... + 161996.

It is an arithmetic number, because the mean of its divisors is an integer number (361806536).

Almost surely, 2^5257661661 is an apocalyptic number.

It is an amenable number.

5257661661 is a deficient number, since it is larger than the sum of its proper divisors (3425695203).

5257661661 is a wasteful number, since it uses less digits than its factorization.

5257661661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38881 (or 38878 counting only the distinct ones).

The product of its digits is 453600, while the sum is 45.

The square root of 5257661661 is about 72509.7349395238. The cubic root of 5257661661 is about 1738.8583761875.

The spelling of 5257661661 in words is "five billion, two hundred fifty-seven million, six hundred sixty-one thousand, six hundred sixty-one".