31212155461 has 4 divisors (see below), whose sum is σ = 31212648000. Its totient is φ = 31211662924.

The previous prime is 31212155339. The next prime is 31212155531. The reversal of 31212155461 is 16455121213.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31212155461 - 2⁹ = 31212154949 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31212155861) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 134221 + ... + 283618.

It is an arithmetic number, because the mean of its divisors is an integer number (7803162000).

Almost surely, 2^31212155461 is an apocalyptic number.

It is an amenable number.

31212155461 is a deficient number, since it is larger than the sum of its proper divisors (492539).

31212155461 is an equidigital number, since it uses as much as digits as its factorization.

31212155461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 492538.

The product of its digits is 7200, while the sum is 31.

Adding to 31212155461 its reverse (16455121213), we get a palindrome (47667276674).

The spelling of 31212155461 in words is "thirty-one billion, two hundred twelve million, one hundred fifty-five thousand, four hundred sixty-one".