61171992820 has 24 divisors (see below), whose sum is σ = 128519483904. Its totient is φ = 24457692576.

The previous prime is 61171992799. The next prime is 61171992853. The reversal of 61171992820 is 2829917116.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 648792 + ... + 737071.

It is an arithmetic number, because the mean of its divisors is an integer number (5354978496).

Almost surely, 2^61171992820 is an apocalyptic number.

It is an amenable number.

61171992820 is an abundant number, since it is smaller than the sum of its proper divisors (67347491084).

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

61171992820 is a wasteful number, since it uses less digits than its factorization.

61171992820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1388079 (or 1388077 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 46.

The spelling of 61171992820 in words is "sixty-one billion, one hundred seventy-one million, nine hundred ninety-two thousand, eight hundred twenty".