31540220051 has 4 divisors (see below), whose sum is σ = 32010969672. Its totient is φ = 31069470432.

The previous prime is 31540220029. The next prime is 31540220069. The reversal of 31540220051 is 15002204513.

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

It is a cyclic number.

It is not a de Polignac number, because 31540220051 - 2²² = 31536025747 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31540219999 and 31540220026.

It is not an unprimeable number, because it can be changed into a prime (31540220351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 235374710 + ... + 235374843.

It is an arithmetic number, because the mean of its divisors is an integer number (8002742418).

Almost surely, 2^31540220051 is an apocalyptic number.

31540220051 is a deficient number, since it is larger than the sum of its proper divisors (470749621).

31540220051 is an equidigital number, since it uses as much as digits as its factorization.

31540220051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 470749620.

The product of its (nonzero) digits is 1200, while the sum is 23.

Adding to 31540220051 its reverse (15002204513), we get a palindrome (46542424564).

The spelling of 31540220051 in words is "thirty-one billion, five hundred forty million, two hundred twenty thousand, fifty-one".