31278304045921 has 2 divisors, whose sum is σ = 31278304045922. Its totient is φ = 31278304045920.

The previous prime is 31278304045907. The next prime is 31278304045969. The reversal of 31278304045921 is 12954040387213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18614392513600 + 12663911532321 = 4314440^2 + 3558639^2 .

It is a cyclic number.

It is not a de Polignac number, because 31278304045921 - 2⁹ = 31278304045409 is a prime.

It is not a weakly prime, because it can be changed into another prime (31278304045991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15639152022960 + 15639152022961.

It is an arithmetic number, because the mean of its divisors is an integer number (15639152022961).

Almost surely, 2^{31278304045921} is an apocalyptic number.

It is an amenable number.

31278304045921 is a deficient number, since it is larger than the sum of its proper divisors (1).

31278304045921 is an equidigital number, since it uses as much as digits as its factorization.

31278304045921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1451520, while the sum is 49.

The spelling of 31278304045921 in words is "thirty-one trillion, two hundred seventy-eight billion, three hundred four million, forty-five thousand, nine hundred twenty-one".