21988149 has 24 divisors (see below), whose sum is σ = 31455360. Its totient is φ = 13658112.

The previous prime is 21988147. The next prime is 21988159. The reversal of 21988149 is 94188912.

It is not a de Polignac number, because 21988149 - 2¹ = 21988147 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21988149.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21988147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 85429 + ... + 85685.

It is an arithmetic number, because the mean of its divisors is an integer number (1310640).

Almost surely, 2^21988149 is an apocalyptic number.

It is an amenable number.

21988149 is a deficient number, since it is larger than the sum of its proper divisors (9467211).

21988149 is a wasteful number, since it uses less digits than its factorization.

21988149 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 377 (or 358 counting only the distinct ones).

The product of its digits is 41472, while the sum is 42.

The square root of 21988149 is about 4689.1522688008. The cubic root of 21988149 is about 280.1536104405.

The spelling of 21988149 in words is "twenty-one million, nine hundred eighty-eight thousand, one hundred forty-nine".