20372355651517 has 4 divisors (see below), whose sum is σ = 20372455597536. Its totient is φ = 20372255705500.

The previous prime is 20372355651509. The next prime is 20372355651547. The reversal of 20372355651517 is 71515655327302.

It is a happy number.

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 20372355651517 - 2³ = 20372355651509 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 (20372355651547) 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, 49666633 + ... + 50075134.

It is an arithmetic number, because the mean of its divisors is an integer number (5093113899384).

Almost surely, 2^{20372355651517} is an apocalyptic number.

It is an amenable number.

20372355651517 is a deficient number, since it is larger than the sum of its proper divisors (99946019).

20372355651517 is an equidigital number, since it uses as much as digits as its factorization.

20372355651517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99946018.

The product of its (nonzero) digits is 6615000, while the sum is 52.

The spelling of 20372355651517 in words is "twenty trillion, three hundred seventy-two billion, three hundred fifty-five million, six hundred fifty-one thousand, five hundred seventeen".