31402289 has 2 divisors, whose sum is σ = 31402290. Its totient is φ = 31402288.

The previous prime is 31402279. The next prime is 31402309. The reversal of 31402289 is 98220413.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22963264 + 8439025 = 4792^2 + 2905^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31402289 is a prime.

It is a super-2 number, since 2×31402289² = 1972207508879042, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31402249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15701144 + 15701145.

It is an arithmetic number, because the mean of its divisors is an integer number (15701145).

Almost surely, 2^31402289 is an apocalyptic number.

It is an amenable number.

31402289 is a deficient number, since it is larger than the sum of its proper divisors (1).

31402289 is an equidigital number, since it uses as much as digits as its factorization.

31402289 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 31402289 is about 5603.7745315100. The cubic root of 31402289 is about 315.4910925477.

The spelling of 31402289 in words is "thirty-one million, four hundred two thousand, two hundred eighty-nine".