31490191 has 4 divisors (see below), whose sum is σ = 31604152. Its totient is φ = 31376232.

The previous prime is 31490189. The next prime is 31490227. The reversal of 31490191 is 19109413.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 31490191 - 2¹ = 31490189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31490131) 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, 56565 + ... + 57118.

It is an arithmetic number, because the mean of its divisors is an integer number (7901038).

Almost surely, 2^31490191 is an apocalyptic number.

31490191 is a deficient number, since it is larger than the sum of its proper divisors (113961).

31490191 is a wasteful number, since it uses less digits than its factorization.

31490191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113960.

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

The square root of 31490191 is about 5611.6121569474. The cubic root of 31490191 is about 315.7851949074.

The spelling of 31490191 in words is "thirty-one million, four hundred ninety thousand, one hundred ninety-one".