21948693 has 16 divisors (see below), whose sum is σ = 32887680. Its totient is φ = 12919104.

The previous prime is 21948673. The next prime is 21948721. The reversal of 21948693 is 39684912.

It is not a de Polignac number, because 21948693 - 2²² = 17754389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21948673) 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, 11338 + ... + 13131.

It is an arithmetic number, because the mean of its divisors is an integer number (2055480).

Almost surely, 2^21948693 is an apocalyptic number.

21948693 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21948693 is a deficient number, since it is larger than the sum of its proper divisors (10938987).

21948693 is a wasteful number, since it uses less digits than its factorization.

21948693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24508.

The product of its digits is 93312, while the sum is 42.

The square root of 21948693 is about 4684.9432227083. The cubic root of 21948693 is about 279.9859389197.

The spelling of 21948693 in words is "twenty-one million, nine hundred forty-eight thousand, six hundred ninety-three".