21469957 has 8 divisors (see below), whose sum is σ = 21844800. Its totient is φ = 21097440.

The previous prime is 21469951. The next prime is 21469961. The reversal of 21469957 is 75996412.

It is a happy number.

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 21469957 - 2¹¹ = 21467909 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 (21469951) 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, 35544 + ... + 36142.

It is an arithmetic number, because the mean of its divisors is an integer number (2730600).

Almost surely, 2^21469957 is an apocalyptic number.

It is an amenable number.

21469957 is a deficient number, since it is larger than the sum of its proper divisors (374843).

21469957 is an equidigital number, since it uses as much as digits as its factorization.

21469957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1163.

The product of its digits is 136080, while the sum is 43.

The square root of 21469957 is about 4633.5684952313. The cubic root of 21469957 is about 277.9353100692.

The spelling of 21469957 in words is "twenty-one million, four hundred sixty-nine thousand, nine hundred fifty-seven".