61666836 has 48 divisors (see below), whose sum is σ = 179397120. Its totient is φ = 16017120.

The previous prime is 61666819. The next prime is 61666861. The reversal of 61666836 is 63866616.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32446 + ... + 34293.

It is an arithmetic number, because the mean of its divisors is an integer number (3737440).

Almost surely, 2^61666836 is an apocalyptic number.

61666836 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

61666836 is an abundant number, since it is smaller than the sum of its proper divisors (117730284).

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

61666836 is a wasteful number, since it uses less digits than its factorization.

61666836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66764 (or 66762 counting only the distinct ones).

The product of its digits is 186624, while the sum is 42.

The square root of 61666836 is about 7852.8234412853. The cubic root of 61666836 is about 395.0789480610.

The spelling of 61666836 in words is "sixty-one million, six hundred sixty-six thousand, eight hundred thirty-six".