21889235 has 24 divisors (see below), whose sum is σ = 28291536. Its totient is φ = 16251840.

The previous prime is 21889223. The next prime is 21889247. The reversal of 21889235 is 53298812.

It is an interprime number because it is at equal distance from previous prime (21889223) and next prime (21889247).

It is not a de Polignac number, because 21889235 - 2¹⁸ = 21627091 is a prime.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 120845 + ... + 121025.

It is an arithmetic number, because the mean of its divisors is an integer number (1178814).

Almost surely, 2^21889235 is an apocalyptic number.

21889235 is a deficient number, since it is larger than the sum of its proper divisors (6402301).

21889235 is a wasteful number, since it uses less digits than its factorization.

21889235 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291 (or 272 counting only the distinct ones).

The product of its digits is 34560, while the sum is 38.

The square root of 21889235 is about 4678.5932714866. The cubic root of 21889235 is about 279.7328872692.

The spelling of 21889235 in words is "twenty-one million, eight hundred eighty-nine thousand, two hundred thirty-five".