21938545 has 8 divisors (see below), whose sum is σ = 27175680. Its totient is φ = 16984560.

The previous prime is 21938533. The next prime is 21938549. The reversal of 21938545 is 54583912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21938545 - 2⁷ = 21938417 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21938549) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70615 + ... + 70924.

It is an arithmetic number, because the mean of its divisors is an integer number (3396960).

Almost surely, 2^21938545 is an apocalyptic number.

It is an amenable number.

21938545 is a deficient number, since it is larger than the sum of its proper divisors (5237135).

21938545 is a wasteful number, since it uses less digits than its factorization.

21938545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141575.

The product of its digits is 43200, while the sum is 37.

The square root of 21938545 is about 4683.8600534175. The cubic root of 21938545 is about 279.9427816755.

The spelling of 21938545 in words is "twenty-one million, nine hundred thirty-eight thousand, five hundred forty-five".