21124949 has 8 divisors (see below), whose sum is σ = 21669120. Its totient is φ = 20584816.

The previous prime is 21124927. The next prime is 21124967. The reversal of 21124949 is 94942112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21124949 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21124969) 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, 11507 + ... + 13215.

It is an arithmetic number, because the mean of its divisors is an integer number (2708640).

Almost surely, 2^21124949 is an apocalyptic number.

It is an amenable number.

21124949 is a deficient number, since it is larger than the sum of its proper divisors (544171).

21124949 is a wasteful number, since it uses less digits than its factorization.

21124949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2019.

The product of its digits is 5184, while the sum is 32.

The square root of 21124949 is about 4596.1885296406. The cubic root of 21124949 is about 276.4385182242.

The spelling of 21124949 in words is "twenty-one million, one hundred twenty-four thousand, nine hundred forty-nine".