126321721634 has 4 divisors (see below), whose sum is σ = 189482582454. Its totient is φ = 63160860816.

The previous prime is 126321721607. The next prime is 126321721637. The reversal of 126321721634 is 436127123621.

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

It can be written as a sum of positive squares in only one way, i.e., 97092690409 + 29229031225 = 311597^2 + 170965^2 .

It is not an unprimeable number, because it can be changed into a prime (126321721637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31580430407 + ... + 31580430410.

Almost surely, 2^126321721634 is an apocalyptic number.

126321721634 is a deficient number, since it is larger than the sum of its proper divisors (63160860820).

126321721634 is an equidigital number, since it uses as much as digits as its factorization.

126321721634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63160860819.

The product of its digits is 72576, while the sum is 38.

The spelling of 126321721634 in words is "one hundred twenty-six billion, three hundred twenty-one million, seven hundred twenty-one thousand, six hundred thirty-four".