31497121 has 4 divisors (see below), whose sum is σ = 31510192. Its totient is φ = 31484052.

The previous prime is 31497083. The next prime is 31497127. The reversal of 31497121 is 12179413.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 12179413 = 277 ⋅43969.

It is a cyclic number.

It is not a de Polignac number, because 31497121 - 2²¹ = 29399969 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31497121.

It is not an unprimeable number, because it can be changed into a prime (31497127) 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, 1755 + ... + 8128.

It is an arithmetic number, because the mean of its divisors is an integer number (7877548).

Almost surely, 2^31497121 is an apocalyptic number.

It is an amenable number.

31497121 is a deficient number, since it is larger than the sum of its proper divisors (13071).

31497121 is an equidigital number, since it uses as much as digits as its factorization.

31497121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13070.

The product of its digits is 1512, while the sum is 28.

The square root of 31497121 is about 5612.2295925951. The cubic root of 31497121 is about 315.8083580028.

The spelling of 31497121 in words is "thirty-one million, four hundred ninety-seven thousand, one hundred twenty-one".