21374057 has 4 divisors (see below), whose sum is σ = 21447300. Its totient is φ = 21300816.

The previous prime is 21374051. The next prime is 21374071. The reversal of 21374057 is 75047312.

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 20939776 + 434281 = 4576^2 + 659^2 .

It is a cyclic number.

It is not a de Polignac number, because 21374057 - 2⁸ = 21373801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21374051) 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, 36182 + ... + 36767.

It is an arithmetic number, because the mean of its divisors is an integer number (5361825).

Almost surely, 2^21374057 is an apocalyptic number.

It is an amenable number.

21374057 is a deficient number, since it is larger than the sum of its proper divisors (73243).

21374057 is an equidigital number, since it uses as much as digits as its factorization.

21374057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73242.

The product of its (nonzero) digits is 5880, while the sum is 29.

The square root of 21374057 is about 4623.2085179018. The cubic root of 21374057 is about 277.5208738999.

The spelling of 21374057 in words is "twenty-one million, three hundred seventy-four thousand, fifty-seven".