126757757621 has 4 divisors (see below), whose sum is σ = 138281190144. Its totient is φ = 115234325100.

The previous prime is 126757757593. The next prime is 126757757629.

126757757621 is nontrivially palindromic in base 10.

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 126757757621 - 2¹⁰ = 126757756597 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 (126757757629) 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, 5761716245 + ... + 5761716266.

It is an arithmetic number, because the mean of its divisors is an integer number (34570297536).

Almost surely, 2^126757757621 is an apocalyptic number.

126757757621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

126757757621 is a deficient number, since it is larger than the sum of its proper divisors (11523432523).

126757757621 is a wasteful number, since it uses less digits than its factorization.

126757757621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11523432522.

The product of its digits is 8643600, while the sum is 56.

The spelling of 126757757621 in words is "one hundred twenty-six billion, seven hundred fifty-seven million, seven hundred fifty-seven thousand, six hundred twenty-one".