61311533631 has 4 divisors (see below), whose sum is σ = 81748711512. Its totient is φ = 40874355752.

The previous prime is 61311533629. The next prime is 61311533659. The reversal of 61311533631 is 13633511316.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 61311533631 - 2¹ = 61311533629 is a prime.

It is a super-2 number, since 2×61311533631² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 61311533592 and 61311533601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61311533611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10218588936 + ... + 10218588941.

It is an arithmetic number, because the mean of its divisors is an integer number (20437177878).

Almost surely, 2^61311533631 is an apocalyptic number.

61311533631 is a deficient number, since it is larger than the sum of its proper divisors (20437177881).

61311533631 is a wasteful number, since it uses less digits than its factorization.

61311533631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20437177880.

The product of its digits is 14580, while the sum is 33.

The spelling of 61311533631 in words is "sixty-one billion, three hundred eleven million, five hundred thirty-three thousand, six hundred thirty-one".