61191660 has 24 divisors (see below), whose sum is σ = 171336816. Its totient is φ = 16317760.

The previous prime is 61191659. The next prime is 61191671. The reversal of 61191660 is 6619116.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 509871 + ... + 509990.

It is an arithmetic number, because the mean of its divisors is an integer number (7139034).

Almost surely, 2^61191660 is an apocalyptic number.

61191660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61191660 is an abundant number, since it is smaller than the sum of its proper divisors (110145156).

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

61191660 is a wasteful number, since it uses less digits than its factorization.

61191660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1019873 (or 1019871 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 61191660 is about 7822.5098274147. The cubic root of 61191660 is about 394.0615654436.

The spelling of 61191660 in words is "sixty-one million, one hundred ninety-one thousand, six hundred sixty".