31719421 has 4 divisors (see below), whose sum is σ = 31774972. Its totient is φ = 31663872.

The previous prime is 31719409. The next prime is 31719437. The reversal of 31719421 is 12491713.

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

It can be written as a sum of positive squares in 2 ways, for example, as 25140196 + 6579225 = 5014^2 + 2565^2 .

It is a cyclic number.

It is not a de Polignac number, because 31719421 - 2¹⁵ = 31686653 is a prime.

It is a super-2 number, since 2×31719421² = 2012243337150482, which contains 22 as substring.

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 31719421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31719221) 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, 26910 + ... + 28063.

It is an arithmetic number, because the mean of its divisors is an integer number (7943743).

Almost surely, 2^31719421 is an apocalyptic number.

It is an amenable number.

31719421 is a deficient number, since it is larger than the sum of its proper divisors (55551).

31719421 is an equidigital number, since it uses as much as digits as its factorization.

31719421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55550.

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

The square root of 31719421 is about 5631.9997336648. Note that the first 3 decimals coincide. The cubic root of 31719421 is about 316.5495863882.

The spelling of 31719421 in words is "thirty-one million, seven hundred nineteen thousand, four hundred twenty-one".