21835057 has 4 divisors (see below), whose sum is σ = 22588020. Its totient is φ = 21082096.

The previous prime is 21835043. The next prime is 21835061. The reversal of 21835057 is 75053812.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7667361 + 14167696 = 2769^2 + 3764^2 .

It is a cyclic number.

It is not a de Polignac number, because 21835057 - 2²³ = 13446449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21835007) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 376438 + ... + 376495.

It is an arithmetic number, because the mean of its divisors is an integer number (5647005).

Almost surely, 2^21835057 is an apocalyptic number.

It is an amenable number.

21835057 is a deficient number, since it is larger than the sum of its proper divisors (752963).

21835057 is an equidigital number, since it uses as much as digits as its factorization.

21835057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 752962.

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 21835057 is about 4672.7996961137. The cubic root of 21835057 is about 279.5019078363.

Adding to 21835057 its reverse (75053812), we get a palindrome (96888869).

The spelling of 21835057 in words is "twenty-one million, eight hundred thirty-five thousand, fifty-seven".