21860638 has 4 divisors (see below), whose sum is σ = 32790960. Its totient is φ = 10930318.

The previous prime is 21860609. The next prime is 21860647. The reversal of 21860638 is 83606812.

21860638 is nontrivially palindromic in base 14.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5465158 + ... + 5465161.

It is an arithmetic number, because the mean of its divisors is an integer number (8197740).

Almost surely, 2^21860638 is an apocalyptic number.

21860638 is a deficient number, since it is larger than the sum of its proper divisors (10930322).

21860638 is a wasteful number, since it uses less digits than its factorization.

21860638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10930321.

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 21860638 is about 4675.5361189921. The cubic root of 21860638 is about 279.6110159850.

The spelling of 21860638 in words is "twenty-one million, eight hundred sixty thousand, six hundred thirty-eight".