31125421 has 8 divisors (see below), whose sum is σ = 32529024. Its totient is φ = 29752800.

The previous prime is 31125403. The next prime is 31125427. The reversal of 31125421 is 12452113.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31125421 - 2⁵ = 31125389 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 (31125427) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5680 + ... + 9721.

It is an arithmetic number, because the mean of its divisors is an integer number (4066128).

Almost surely, 2^31125421 is an apocalyptic number.

It is an amenable number.

31125421 is a deficient number, since it is larger than the sum of its proper divisors (1403603).

31125421 is a wasteful number, since it uses less digits than its factorization.

31125421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15491.

The product of its digits is 240, while the sum is 19.

The square root of 31125421 is about 5579.0161319000. The cubic root of 31125421 is about 314.5611458273.

Adding to 31125421 its reverse (12452113), we get a palindrome (43577534).

The spelling of 31125421 in words is "thirty-one million, one hundred twenty-five thousand, four hundred twenty-one".