31161551 has 2 divisors, whose sum is σ = 31161552. Its totient is φ = 31161550.

The previous prime is 31161521. The next prime is 31161569. The reversal of 31161551 is 15516113.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31161551 - 2¹⁰ = 31160527 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 (31161521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15580775 + 15580776.

It is an arithmetic number, because the mean of its divisors is an integer number (15580776).

Almost surely, 2^31161551 is an apocalyptic number.

31161551 is a deficient number, since it is larger than the sum of its proper divisors (1).

31161551 is an equidigital number, since it uses as much as digits as its factorization.

31161551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 450, while the sum is 23.

The square root of 31161551 is about 5582.2532189072. The cubic root of 31161551 is about 314.6828116467.

Adding to 31161551 its reverse (15516113), we get a palindrome (46677664).

The spelling of 31161551 in words is "thirty-one million, one hundred sixty-one thousand, five hundred fifty-one".