61985562961 has 15 divisors (see below), whose sum is σ = 72326422043. Its totient is φ = 53120025840.

The previous prime is 61985562937. The next prime is 61985562997. The reversal of 61985562961 is 16926558916.

The square root of 61985562961 is 248969.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 8495124561 + 53490438400 = 92169^2 + 231280^2 .

It is not a de Polignac number, because 61985562961 - 2¹⁵ = 61985530193 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 61985562896 and 61985562905.

It is not an unprimeable number, because it can be changed into a prime (61985560961) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 12196941 + ... + 12202021.

Almost surely, 2^61985562961 is an apocalyptic number.

61985562961 is the 248969-th square number.

61985562961 is the 124485-th centered octagonal number.

It is an amenable number.

61985562961 is a deficient number, since it is larger than the sum of its proper divisors (10340859082).

61985562961 is an frugal number, since it uses more digits than its factorization.

61985562961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10190 (or 5088 counting only the distinct ones).

The product of its digits is 6998400, while the sum is 58.

The spelling of 61985562961 in words is "sixty-one billion, nine hundred eighty-five million, five hundred sixty-two thousand, nine hundred sixty-one".