20531555770251 has 16 divisors (see below), whose sum is σ = 29173422449664. Its totient is φ = 12814020620544.

The previous prime is 20531555770247. The next prime is 20531555770261. The reversal of 20531555770251 is 15207755513502.

It is not a de Polignac number, because 20531555770251 - 2² = 20531555770247 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20531555770251.

It is not an unprimeable number, because it can be changed into a prime (20531555770211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3165515686 + ... + 3165522171.

It is an arithmetic number, because the mean of its divisors is an integer number (1823338903104).

Almost surely, 2^{20531555770251} is an apocalyptic number.

20531555770251 is a deficient number, since it is larger than the sum of its proper divisors (8641866679413).

20531555770251 is a wasteful number, since it uses less digits than its factorization.

20531555770251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6331037930.

The product of its (nonzero) digits is 1837500, while the sum is 48.

The spelling of 20531555770251 in words is "twenty trillion, five hundred thirty-one billion, five hundred fifty-five million, seven hundred seventy thousand, two hundred fifty-one".