61123636521 has 12 divisors (see below), whose sum is σ = 88338743220. Its totient is φ = 40726454400.

The previous prime is 61123636507. The next prime is 61123636529. The reversal of 61123636521 is 12563632116.

61123636521 is a `hidden beast` number, since 6 + 1 + 12 + 3 + 636 + 5 + 2 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 17666397225 + 43457239296 = 132915^2 + 208464^2 .

It is not a de Polignac number, because 61123636521 - 2⁷ = 61123636393 is a prime.

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

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1869276 + ... + 1901693.

It is an arithmetic number, because the mean of its divisors is an integer number (7361561935).

Almost surely, 2^61123636521 is an apocalyptic number.

It is an amenable number.

61123636521 is a deficient number, since it is larger than the sum of its proper divisors (27215106699).

61123636521 is a wasteful number, since it uses less digits than its factorization.

61123636521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3772776 (or 3772773 counting only the distinct ones).

The product of its digits is 38880, while the sum is 36.

The spelling of 61123636521 in words is "sixty-one billion, one hundred twenty-three million, six hundred thirty-six thousand, five hundred twenty-one".