21934015 has 4 divisors (see below), whose sum is σ = 26320824. Its totient is φ = 17547208.

The previous prime is 21934013. The next prime is 21934039. The reversal of 21934015 is 51043912.

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 21934015 - 2¹ = 21934013 is a prime.

It is a super-2 number, since 2×21934015² = 962202028040450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21934013) 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, 2193397 + ... + 2193406.

It is an arithmetic number, because the mean of its divisors is an integer number (6580206).

Almost surely, 2^21934015 is an apocalyptic number.

21934015 is a deficient number, since it is larger than the sum of its proper divisors (4386809).

21934015 is an equidigital number, since it uses as much as digits as its factorization.

21934015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4386808.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 21934015 is about 4683.3764529450. The cubic root of 21934015 is about 279.9235122710.

Adding to 21934015 its reverse (51043912), we get a palindrome (72977927).

The spelling of 21934015 in words is "twenty-one million, nine hundred thirty-four thousand, fifteen".