126247635521 has 4 divisors (see below), whose sum is σ = 144283012032. Its totient is φ = 108212259012.

The previous prime is 126247635469. The next prime is 126247635523. The reversal of 126247635521 is 125536742621.

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 a de Polignac number, because none of the positive numbers 2^k-126247635521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (126247635523) 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, 9017688245 + ... + 9017688258.

It is an arithmetic number, because the mean of its divisors is an integer number (36070753008).

Almost surely, 2^126247635521 is an apocalyptic number.

It is an amenable number.

126247635521 is a deficient number, since it is larger than the sum of its proper divisors (18035376511).

126247635521 is an equidigital number, since it uses as much as digits as its factorization.

126247635521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18035376510.

The product of its digits is 604800, while the sum is 44.

The spelling of 126247635521 in words is "one hundred twenty-six billion, two hundred forty-seven million, six hundred thirty-five thousand, five hundred twenty-one".