631270021 has 2 divisors, whose sum is σ = 631270022. Its totient is φ = 631270020.

The previous prime is 631270007. The next prime is 631270033. The reversal of 631270021 is 120072136.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 622502500 + 8767521 = 24950^2 + 2961^2 .

It is a cyclic number.

It is not a de Polignac number, because 631270021 - 2⁷ = 631269893 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 631269974 and 631270001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (631270001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315635010 + 315635011.

It is an arithmetic number, because the mean of its divisors is an integer number (315635011).

Almost surely, 2^631270021 is an apocalyptic number.

It is an amenable number.

631270021 is a deficient number, since it is larger than the sum of its proper divisors (1).

631270021 is an equidigital number, since it uses as much as digits as its factorization.

631270021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 631270021 is about 25125.0874824348. The cubic root of 631270021 is about 857.8375548023.

The spelling of 631270021 in words is "six hundred thirty-one million, two hundred seventy thousand, twenty-one".