21921395 has 8 divisors (see below), whose sum is σ = 26698704. Its totient is φ = 17275104.

The previous prime is 21921377. The next prime is 21921397. The reversal of 21921395 is 59312912.

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 21921395 - 2¹⁴ = 21905011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21921397) 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, 32384 + ... + 33053.

It is an arithmetic number, because the mean of its divisors is an integer number (3337338).

Almost surely, 2^21921395 is an apocalyptic number.

21921395 is a deficient number, since it is larger than the sum of its proper divisors (4777309).

21921395 is an equidigital number, since it uses as much as digits as its factorization.

21921395 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65509.

The product of its digits is 4860, while the sum is 32.

The square root of 21921395 is about 4682.0289405342. The cubic root of 21921395 is about 279.8698161821.

The spelling of 21921395 in words is "twenty-one million, nine hundred twenty-one thousand, three hundred ninety-five".