31006157491 has 2 divisors, whose sum is σ = 31006157492. Its totient is φ = 31006157490.

The previous prime is 31006157471. The next prime is 31006157543. The reversal of 31006157491 is 19475160013.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31006157491 - 2¹³ = 31006149299 is a prime.

It is a super-2 number, since 2×31006157491² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31006157491.

It is not a weakly prime, because it can be changed into another prime (31006157431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15503078745 + 15503078746.

It is an arithmetic number, because the mean of its divisors is an integer number (15503078746).

Almost surely, 2^31006157491 is an apocalyptic number.

31006157491 is a deficient number, since it is larger than the sum of its proper divisors (1).

31006157491 is an equidigital number, since it uses as much as digits as its factorization.

31006157491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22680, while the sum is 37.

The spelling of 31006157491 in words is "thirty-one billion, six million, one hundred fifty-seven thousand, four hundred ninety-one".