21372661781041 has 4 divisors (see below), whose sum is σ = 21827399265792. Its totient is φ = 20917924296292.

The previous prime is 21372661780991. The next prime is 21372661781059. The reversal of 21372661781041 is 14018716627312.

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 21372661781041 - 2³⁹ = 20822905967153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21372661731041) 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, 227368742305 + ... + 227368742398.

It is an arithmetic number, because the mean of its divisors is an integer number (5456849816448).

Almost surely, 2^{21372661781041} is an apocalyptic number.

It is an amenable number.

21372661781041 is a deficient number, since it is larger than the sum of its proper divisors (454737484751).

21372661781041 is an equidigital number, since it uses as much as digits as its factorization.

21372661781041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454737484750.

The product of its (nonzero) digits is 677376, while the sum is 49.

The spelling of 21372661781041 in words is "twenty-one trillion, three hundred seventy-two billion, six hundred sixty-one million, seven hundred eighty-one thousand, forty-one".