21939253 has 8 divisors (see below), whose sum is σ = 25155072. Its totient is φ = 18743856.

The previous prime is 21939241. The next prime is 21939277. The reversal of 21939253 is 35293912.

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 21939253 - 2¹³ = 21931061 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 (21939233) 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, 2725 + ... + 7162.

It is an arithmetic number, because the mean of its divisors is an integer number (3144384).

Almost surely, 2^21939253 is an apocalyptic number.

It is an amenable number.

21939253 is a deficient number, since it is larger than the sum of its proper divisors (3215819).

21939253 is an equidigital number, since it uses as much as digits as its factorization.

21939253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10211.

The product of its digits is 14580, while the sum is 34.

The square root of 21939253 is about 4683.9356314962. The cubic root of 21939253 is about 279.9457930779.

The spelling of 21939253 in words is "twenty-one million, nine hundred thirty-nine thousand, two hundred fifty-three".