20520919655 has 4 divisors (see below), whose sum is σ = 24625103592. Its totient is φ = 16416735720.

The previous prime is 20520919649. The next prime is 20520919663. The reversal of 20520919655 is 55691902502.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20520919655 - 2⁸ = 20520919399 is a prime.

It is a super-2 number, since 2×20520919655² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2052091961 + ... + 2052091970.

It is an arithmetic number, because the mean of its divisors is an integer number (6156275898).

Almost surely, 2^20520919655 is an apocalyptic number.

20520919655 is a deficient number, since it is larger than the sum of its proper divisors (4104183937).

20520919655 is an equidigital number, since it uses as much as digits as its factorization.

20520919655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4104183936.

The product of its (nonzero) digits is 243000, while the sum is 44.

The spelling of 20520919655 in words is "twenty billion, five hundred twenty million, nine hundred nineteen thousand, six hundred fifty-five".