31873421 has 2 divisors, whose sum is σ = 31873422. Its totient is φ = 31873420.

The previous prime is 31873357. The next prime is 31873427. The reversal of 31873421 is 12437813.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31866025 + 7396 = 5645^2 + 86^2 .

It is a cyclic number.

It is not a de Polignac number, because 31873421 - 2⁶ = 31873357 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31873427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15936710 + 15936711.

It is an arithmetic number, because the mean of its divisors is an integer number (15936711).

Almost surely, 2^31873421 is an apocalyptic number.

It is an amenable number.

31873421 is a deficient number, since it is larger than the sum of its proper divisors (1).

31873421 is an equidigital number, since it uses as much as digits as its factorization.

31873421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4032, while the sum is 29.

The square root of 31873421 is about 5645.6550549958. The cubic root of 31873421 is about 317.0610496517.

The spelling of 31873421 in words is "thirty-one million, eight hundred seventy-three thousand, four hundred twenty-one".