126131578621 has 4 divisors (see below), whose sum is σ = 126464380000. Its totient is φ = 125798777244.

The previous prime is 126131578613. The next prime is 126131578669. The reversal of 126131578621 is 126875131621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 126131578621 - 2³ = 126131578613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (126131578121) 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, 166400121 + ... + 166400878.

It is an arithmetic number, because the mean of its divisors is an integer number (31616095000).

Almost surely, 2^126131578621 is an apocalyptic number.

It is an amenable number.

126131578621 is a deficient number, since it is larger than the sum of its proper divisors (332801379).

126131578621 is an equidigital number, since it uses as much as digits as its factorization.

126131578621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332801378.

The product of its digits is 120960, while the sum is 43.

The spelling of 126131578621 in words is "one hundred twenty-six billion, one hundred thirty-one million, five hundred seventy-eight thousand, six hundred twenty-one".