31109491 has 4 divisors (see below), whose sum is σ = 35553712. Its totient is φ = 26665272.

The previous prime is 31109483. The next prime is 31109509. The reversal of 31109491 is 19490113.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19490113 = 97 ⋅200929.

It is a cyclic number.

It is not a de Polignac number, because 31109491 - 2³ = 31109483 is a prime.

It is a super-3 number, since 3×31109491³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31109401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2222100 + ... + 2222113.

It is an arithmetic number, because the mean of its divisors is an integer number (8888428).

Almost surely, 2^31109491 is an apocalyptic number.

31109491 is a deficient number, since it is larger than the sum of its proper divisors (4444221).

31109491 is an equidigital number, since it uses as much as digits as its factorization.

31109491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4444220.

The product of its (nonzero) digits is 972, while the sum is 28.

The square root of 31109491 is about 5577.5882781001. The cubic root of 31109491 is about 314.5074725060.

The spelling of 31109491 in words is "thirty-one million, one hundred nine thousand, four hundred ninety-one".