21693371 has 16 divisors (see below), whose sum is σ = 25665024. Its totient is φ = 17950464.

The previous prime is 21693361. The next prime is 21693379. The reversal of 21693371 is 17339612.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-21693371 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21693379) 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 15 ways as a sum of consecutive naturals, for example, 28826 + ... + 29568.

It is an arithmetic number, because the mean of its divisors is an integer number (1604064).

Almost surely, 2^21693371 is an apocalyptic number.

21693371 is a deficient number, since it is larger than the sum of its proper divisors (3971653).

21693371 is an equidigital number, since it uses as much as digits as its factorization.

21693371 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 890.

The product of its digits is 6804, while the sum is 32.

The square root of 21693371 is about 4657.6143034820. The cubic root of 21693371 is about 278.8960400265.

The spelling of 21693371 in words is "twenty-one million, six hundred ninety-three thousand, three hundred seventy-one".