61113278521 has 9 divisors (see below), whose sum is σ = 61408130511. Its totient is φ = 60819839064.

The previous prime is 61113278453. The next prime is 61113278533. The reversal of 61113278521 is 12587231116.

The square root of 61113278521 is 247211.

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., 4020954921 + 57092323600 = 63411^2 + 238940^2 .

It is not a de Polignac number, because 61113278521 - 2¹¹ = 61113276473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61113278561) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 66499300 + ... + 66500218.

Almost surely, 2^61113278521 is an apocalyptic number.

61113278521 is the 247211-st square number.

61113278521 is the 123606-th centered octagonal number.

It is an amenable number.

61113278521 is a deficient number, since it is larger than the sum of its proper divisors (294851990).

61113278521 is an frugal number, since it uses more digits than its factorization.

61113278521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2376 (or 1188 counting only the distinct ones).

The product of its digits is 20160, while the sum is 37.

The spelling of 61113278521 in words is "sixty-one billion, one hundred thirteen million, two hundred seventy-eight thousand, five hundred twenty-one".