61957198836 has 144 divisors (see below), whose sum is σ = 184168857600. Its totient is φ = 17942266368.

The previous prime is 61957198829. The next prime is 61957198861. The reversal of 61957198836 is 63889175916.

61957198836 is a `hidden beast` number, since 619 + 5 + 7 + 1 + 9 + 8 + 8 + 3 + 6 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 210445 + ... + 410123.

It is an arithmetic number, because the mean of its divisors is an integer number (1278950400).

Almost surely, 2^61957198836 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61957198836, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92084428800).

61957198836 is an abundant number, since it is smaller than the sum of its proper divisors (122211658764).

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

61957198836 is a wasteful number, since it uses less digits than its factorization.

61957198836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199735 (or 199714 counting only the distinct ones).

The product of its digits is 19595520, while the sum is 63.

The spelling of 61957198836 in words is "sixty-one billion, nine hundred fifty-seven million, one hundred ninety-eight thousand, eight hundred thirty-six".