21038417 has 4 divisors (see below), whose sum is σ = 21231540. Its totient is φ = 20845296.

The previous prime is 21038393. The next prime is 21038419. The reversal of 21038417 is 71483012.

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 10042561 + 10995856 = 3169^2 + 3316^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21038417 is a prime.

It is a super-2 number, since 2×21038417² = 885229979731778, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21038419) 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, 96398 + ... + 96615.

It is an arithmetic number, because the mean of its divisors is an integer number (5307885).

Almost surely, 2^21038417 is an apocalyptic number.

It is an amenable number.

21038417 is a deficient number, since it is larger than the sum of its proper divisors (193123).

21038417 is a wasteful number, since it uses less digits than its factorization.

21038417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193122.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 21038417 is about 4586.7654180261. The cubic root of 21038417 is about 276.0605525967.

The spelling of 21038417 in words is "twenty-one million, thirty-eight thousand, four hundred seventeen".