21337427 has 4 divisors (see below), whose sum is σ = 21364056. Its totient is φ = 21310800.

The previous prime is 21337369. The next prime is 21337439. The reversal of 21337427 is 72473312.

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

It is a cyclic number.

It is not a de Polignac number, because 21337427 - 2¹⁶ = 21271891 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21337427.

It is not an unprimeable number, because it can be changed into a prime (21337447) 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, 12074 + ... + 13727.

It is an arithmetic number, because the mean of its divisors is an integer number (5341014).

Almost surely, 2^21337427 is an apocalyptic number.

21337427 is a deficient number, since it is larger than the sum of its proper divisors (26629).

21337427 is an equidigital number, since it uses as much as digits as its factorization.

21337427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26628.

The product of its digits is 7056, while the sum is 29.

The square root of 21337427 is about 4619.2452846758. The cubic root of 21337427 is about 277.3622485428.

The spelling of 21337427 in words is "twenty-one million, three hundred thirty-seven thousand, four hundred twenty-seven".