75212615561 has 4 divisors (see below), whose sum is σ = 75228004500. Its totient is φ = 75197226624.

The previous prime is 75212615549. The next prime is 75212615563. The reversal of 75212615561 is 16551621257.

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

It can be written as a sum of positive squares in 2 ways, for example, as 57080377225 + 18132238336 = 238915^2 + 134656^2 .

It is a cyclic number.

It is not a de Polignac number, because 75212615561 - 2¹⁰ = 75212614537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (75212615563) 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, 7687136 + ... + 7696913.

It is an arithmetic number, because the mean of its divisors is an integer number (18807001125).

Almost surely, 2^75212615561 is an apocalyptic number.

It is an amenable number.

75212615561 is a deficient number, since it is larger than the sum of its proper divisors (15388939).

75212615561 is a wasteful number, since it uses less digits than its factorization.

75212615561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15388938.

The product of its digits is 126000, while the sum is 41.

The spelling of 75212615561 in words is "seventy-five billion, two hundred twelve million, six hundred fifteen thousand, five hundred sixty-one".