1252661661 has 24 divisors (see below), whose sum is σ = 1820819520. Its totient is φ = 829857600.

The previous prime is 1252661611. The next prime is 1252661701. The reversal of 1252661661 is 1661662521.

1252661661 is a `hidden beast` number, since 12 + 5 + 26 + 616 + 6 + 1 = 666.

It is not a de Polignac number, because 1252661661 - 2¹⁵ = 1252628893 is a prime.

It is a super-2 number, since 2×1252661661² = 3138322473878557842, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1252661611) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1457850 + ... + 1458708.

It is an arithmetic number, because the mean of its divisors is an integer number (75867480).

Almost surely, 2^1252661661 is an apocalyptic number.

It is an amenable number.

1252661661 is a deficient number, since it is larger than the sum of its proper divisors (568157859).

1252661661 is a wasteful number, since it uses less digits than its factorization.

1252661661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1697 (or 1694 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 1252661661 is about 35392.9606136588. The cubic root of 1252661661 is about 1077.9813862795.

The spelling of 1252661661 in words is "one billion, two hundred fifty-two million, six hundred sixty-one thousand, six hundred sixty-one".