61123636520 has 32 divisors (see below), whose sum is σ = 138889856520. Its totient is φ = 24207379200.

The previous prime is 61123636507. The next prime is 61123636529. The reversal of 61123636520 is 2563632116.

It can be written as a sum of positive squares in 4 ways, for example, as 60923074276 + 200562244 = 246826^2 + 14162^2 .

It is not an unprimeable number, because it can be changed into a prime (61123636529) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7560767 + ... + 7568846.

Almost surely, 2^61123636520 is an apocalyptic number.

It is an amenable number.

61123636520 is an abundant number, since it is smaller than the sum of its proper divisors (77766220000).

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

61123636520 is a wasteful number, since it uses less digits than its factorization.

61123636520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15129725 (or 15129721 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 35.

The spelling of 61123636520 in words is "sixty-one billion, one hundred twenty-three million, six hundred thirty-six thousand, five hundred twenty".