31155213005 has 32 divisors (see below), whose sum is σ = 43275181824. Its totient is φ = 21090940416.

The previous prime is 31155212983. The next prime is 31155213029. The reversal of 31155213005 is 50031255113.

It is a happy number.

It is not a de Polignac number, because 31155213005 - 2¹⁸ = 31154950861 is a prime.

It is a super-2 number, since 2×31155213005² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1083089 + ... + 1111481.

It is an arithmetic number, because the mean of its divisors is an integer number (1352349432).

Almost surely, 2^31155213005 is an apocalyptic number.

31155213005 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

31155213005 is a deficient number, since it is larger than the sum of its proper divisors (12119968819).

31155213005 is a wasteful number, since it uses less digits than its factorization.

31155213005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28805.

The product of its (nonzero) digits is 2250, while the sum is 26.

Adding to 31155213005 its reverse (50031255113), we get a palindrome (81186468118).

The spelling of 31155213005 in words is "thirty-one billion, one hundred fifty-five million, two hundred thirteen thousand, five".