1253921661 has 32 divisors (see below), whose sum is σ = 1873497600. Its totient is φ = 828861120.

The previous prime is 1253921653. The next prime is 1253921677. The reversal of 1253921661 is 1661293521.

It is not a de Polignac number, because 1253921661 - 2³ = 1253921653 is a prime.

It is a super-3 number, since 3×1253921661³ (a number of 28 digits) contains 333 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 (1253921621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2909116 + ... + 2909546.

It is an arithmetic number, because the mean of its divisors is an integer number (58546800).

Almost surely, 2^1253921661 is an apocalyptic number.

It is an amenable number.

1253921661 is a deficient number, since it is larger than the sum of its proper divisors (619575939).

1253921661 is a wasteful number, since it uses less digits than its factorization.

1253921661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1106 (or 1100 counting only the distinct ones).

The product of its digits is 19440, while the sum is 36.

The square root of 1253921661 is about 35410.7562895796. The cubic root of 1253921661 is about 1078.3426973019.

The spelling of 1253921661 in words is "one billion, two hundred fifty-three million, nine hundred twenty-one thousand, six hundred sixty-one".