31284421 has 4 divisors (see below), whose sum is σ = 35753632. Its totient is φ = 26815212.

The previous prime is 31284419. The next prime is 31284467. The reversal of 31284421 is 12448213.

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.

It is a cyclic number.

It is not a de Polignac number, because 31284421 - 2¹ = 31284419 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 (31284401) 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, 2234595 + ... + 2234608.

It is an arithmetic number, because the mean of its divisors is an integer number (8938408).

Almost surely, 2^31284421 is an apocalyptic number.

It is an amenable number.

31284421 is a deficient number, since it is larger than the sum of its proper divisors (4469211).

31284421 is an equidigital number, since it uses as much as digits as its factorization.

31284421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4469210.

The product of its digits is 1536, while the sum is 25.

The square root of 31284421 is about 5593.2478042726. The cubic root of 31284421 is about 315.0958673521.

The spelling of 31284421 in words is "thirty-one million, two hundred eighty-four thousand, four hundred twenty-one".