21932149 has 4 divisors (see below), whose sum is σ = 22688460. Its totient is φ = 21175840.

The previous prime is 21932147. The next prime is 21932153. The reversal of 21932149 is 94123912.

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

It can be written as a sum of positive squares in 2 ways, for example, as 11009124 + 10923025 = 3318^2 + 3305^2 .

It is a cyclic number.

It is not a de Polignac number, because 21932149 - 2¹ = 21932147 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21932149.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21932143) 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 3 ways as a sum of consecutive naturals, for example, 378112 + ... + 378169.

It is an arithmetic number, because the mean of its divisors is an integer number (5672115).

Almost surely, 2^21932149 is an apocalyptic number.

21932149 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

21932149 is a deficient number, since it is larger than the sum of its proper divisors (756311).

21932149 is an equidigital number, since it uses as much as digits as its factorization.

21932149 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 756310.

The product of its digits is 3888, while the sum is 31.

The square root of 21932149 is about 4683.1772334602. The cubic root of 21932149 is about 279.9155740361.

The spelling of 21932149 in words is "twenty-one million, nine hundred thirty-two thousand, one hundred forty-nine".