20450665221555 has 16 divisors (see below), whose sum is σ = 32726384135424. Its totient is φ = 10905248191200.

The previous prime is 20450665221439. The next prime is 20450665221587. The reversal of 20450665221555 is 55512256605402.

It is a happy number.

It is not a de Polignac number, because 20450665221555 - 2²⁷ = 20450531003827 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 110733429 + ... + 110917958.

It is an arithmetic number, because the mean of its divisors is an integer number (2045399008464).

Almost surely, 2^{20450665221555} is an apocalyptic number.

20450665221555 is a deficient number, since it is larger than the sum of its proper divisors (12275718913869).

20450665221555 is a wasteful number, since it uses less digits than its factorization.

20450665221555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221657546.

The product of its (nonzero) digits is 3600000, while the sum is 48.

The spelling of 20450665221555 in words is "twenty trillion, four hundred fifty billion, six hundred sixty-five million, two hundred twenty-one thousand, five hundred fifty-five".