1661253252 has 72 divisors (see below), whose sum is σ = 4022620896. Its totient is φ = 533280000.

The previous prime is 1661253221. The next prime is 1661253257. The reversal of 1661253252 is 2523521661.

It is not an unprimeable number, because it can be changed into a prime (1661253257) 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, 5018727 + ... + 5019057.

Almost surely, 2^1661253252 is an apocalyptic number.

1661253252 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1661253252 is an abundant number, since it is smaller than the sum of its proper divisors (2361367644).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1661253252 is a wasteful number, since it uses less digits than its factorization.

1661253252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 581 (or 478 counting only the distinct ones).

The product of its digits is 21600, while the sum is 33.

The square root of 1661253252 is about 40758.4746034490. The cubic root of 1661253252 is about 1184.3460466250.

The spelling of 1661253252 in words is "one billion, six hundred sixty-one million, two hundred fifty-three thousand, two hundred fifty-two".