21951189 has 16 divisors (see below), whose sum is σ = 35022400. Its totient is φ = 13508208.

The previous prime is 21951187. The next prime is 21951203. The reversal of 21951189 is 98115912.

It is not a de Polignac number, because 21951189 - 2¹ = 21951187 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21951187) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30919 + ... + 31620.

It is an arithmetic number, because the mean of its divisors is an integer number (2188900).

Almost surely, 2^21951189 is an apocalyptic number.

It is an amenable number.

21951189 is a deficient number, since it is larger than the sum of its proper divisors (13071211).

21951189 is a wasteful number, since it uses less digits than its factorization.

21951189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62561 (or 62555 counting only the distinct ones).

The product of its digits is 6480, while the sum is 36.

The square root of 21951189 is about 4685.2096004341. The cubic root of 21951189 is about 279.9965518283.

The spelling of 21951189 in words is "twenty-one million, nine hundred fifty-one thousand, one hundred eighty-nine".