31505151421 has 2 divisors, whose sum is σ = 31505151422. Its totient is φ = 31505151420.

The previous prime is 31505151389. The next prime is 31505151481. The reversal of 31505151421 is 12415150513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31492406521 + 12744900 = 177461^2 + 3570^2 .

It is an emirp because it is prime and its reverse (12415150513) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31505151421 - 2⁵ = 31505151389 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31505151421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31505151481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15752575710 + 15752575711.

It is an arithmetic number, because the mean of its divisors is an integer number (15752575711).

Almost surely, 2^31505151421 is an apocalyptic number.

It is an amenable number.

31505151421 is a deficient number, since it is larger than the sum of its proper divisors (1).

31505151421 is an equidigital number, since it uses as much as digits as its factorization.

31505151421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3000, while the sum is 28.

The spelling of 31505151421 in words is "thirty-one billion, five hundred five million, one hundred fifty-one thousand, four hundred twenty-one".