31920797 has 2 divisors, whose sum is σ = 31920798. Its totient is φ = 31920796.

The previous prime is 31920761. The next prime is 31920809. The reversal of 31920797 is 79702913.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20557156 + 11363641 = 4534^2 + 3371^2 .

It is an emirp because it is prime and its reverse (79702913) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31920797 - 2¹⁰ = 31919773 is a prime.

It is a super-2 number, since 2×31920797² = 2037874562230418, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31920797.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31920727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15960398 + 15960399.

It is an arithmetic number, because the mean of its divisors is an integer number (15960399).

Almost surely, 2^31920797 is an apocalyptic number.

It is an amenable number.

31920797 is a deficient number, since it is larger than the sum of its proper divisors (1).

31920797 is an equidigital number, since it uses as much as digits as its factorization.

31920797 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23814, while the sum is 38.

The square root of 31920797 is about 5649.8492900254. The cubic root of 31920797 is about 317.2180628998.

The spelling of 31920797 in words is "thirty-one million, nine hundred twenty thousand, seven hundred ninety-seven".