21146430370757 has 4 divisors (see below), whose sum is σ = 21146502783660. Its totient is φ = 21146357957856.

The previous prime is 21146430370693. The next prime is 21146430370889. The reversal of 21146430370757 is 75707303464112.

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 18043456522081 + 3102973848676 = 4247759^2 + 1761526^2 .

It is a cyclic number.

It is not a de Polignac number, because 21146430370757 - 2⁶ = 21146430370693 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 (21146430370057) 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, 35766632 + ... + 36353057.

It is an arithmetic number, because the mean of its divisors is an integer number (5286625695915).

Almost surely, 2^{21146430370757} is an apocalyptic number.

It is an amenable number.

21146430370757 is a deficient number, since it is larger than the sum of its proper divisors (72412903).

21146430370757 is an equidigital number, since it uses as much as digits as its factorization.

21146430370757 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72412902.

The product of its (nonzero) digits is 2963520, while the sum is 50.

The spelling of 21146430370757 in words is "twenty-one trillion, one hundred forty-six billion, four hundred thirty million, three hundred seventy thousand, seven hundred fifty-seven".