31220421 has 8 divisors (see below), whose sum is σ = 42197760. Its totient is φ = 20528352.

The previous prime is 31220419. The next prime is 31220429. The reversal of 31220421 is 12402213.

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

It is not a de Polignac number, because 31220421 - 2¹ = 31220419 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31220421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31220429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 71061 + ... + 71498.

It is an arithmetic number, because the mean of its divisors is an integer number (5274720).

Almost surely, 2^31220421 is an apocalyptic number.

It is an amenable number.

31220421 is a deficient number, since it is larger than the sum of its proper divisors (10977339).

31220421 is a wasteful number, since it uses less digits than its factorization.

31220421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142635.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 31220421 is about 5587.5236912249. The cubic root of 31220421 is about 314.8808518895.

Adding to 31220421 its reverse (12402213), we get a palindrome (43622634).

The spelling of 31220421 in words is "thirty-one million, two hundred twenty thousand, four hundred twenty-one".