31550420155 has 4 divisors (see below), whose sum is σ = 37860504192. Its totient is φ = 25240336120.

The previous prime is 31550420129. The next prime is 31550420171. The reversal of 31550420155 is 55102405513.

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

It is a de Polignac number, because none of the positive numbers 2^k-31550420155 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

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, 3155042011 + ... + 3155042020.

It is an arithmetic number, because the mean of its divisors is an integer number (9465126048).

Almost surely, 2^31550420155 is an apocalyptic number.

31550420155 is a deficient number, since it is larger than the sum of its proper divisors (6310084037).

31550420155 is an equidigital number, since it uses as much as digits as its factorization.

31550420155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6310084036.

The product of its (nonzero) digits is 15000, while the sum is 31.

Adding to 31550420155 its reverse (55102405513), we get a palindrome (86652825668).

The spelling of 31550420155 in words is "thirty-one billion, five hundred fifty million, four hundred twenty thousand, one hundred fifty-five".