31503454155421 has 2 divisors, whose sum is σ = 31503454155422. Its totient is φ = 31503454155420.

The previous prime is 31503454155391. The next prime is 31503454155463. The reversal of 31503454155421 is 12455145430513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30476869783396 + 1026584372025 = 5520586^2 + 1013205^2 .

It is a cyclic number.

It is not a de Polignac number, because 31503454155421 - 2⁵ = 31503454155389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31503454155821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15751727077710 + 15751727077711.

It is an arithmetic number, because the mean of its divisors is an integer number (15751727077711).

Almost surely, 2^{31503454155421} is an apocalyptic number.

It is an amenable number.

31503454155421 is a deficient number, since it is larger than the sum of its proper divisors (1).

31503454155421 is an equidigital number, since it uses as much as digits as its factorization.

31503454155421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720000, while the sum is 43.

Adding to 31503454155421 its reverse (12455145430513), we get a palindrome (43958599585934).

The spelling of 31503454155421 in words is "thirty-one trillion, five hundred three billion, four hundred fifty-four million, one hundred fifty-five thousand, four hundred twenty-one".