1661015172 has 24 divisors (see below), whose sum is σ = 3876364800. Its totient is φ = 553577056.

The previous prime is 1661015171. The next prime is 1661015179. The reversal of 1661015172 is 2715101661.

It is a super-2 number, since 2×1661015172² = 5517942803228379168, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1661015171) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 120154 + ... + 133262.

It is an arithmetic number, because the mean of its divisors is an integer number (161515200).

Almost surely, 2^1661015172 is an apocalyptic number.

1661015172 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1661015172 is an abundant number, since it is smaller than the sum of its proper divisors (2215349628).

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

1661015172 is a wasteful number, since it uses less digits than its factorization.

1661015172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23675 (or 23673 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 30.

The square root of 1661015172 is about 40755.5538791954. The cubic root of 1661015172 is about 1184.2894663339.

The spelling of 1661015172 in words is "one billion, six hundred sixty-one million, fifteen thousand, one hundred seventy-two".