20621249 has 4 divisors (see below), whose sum is σ = 22495920. Its totient is φ = 18746580.

The previous prime is 20621243. The next prime is 20621261. The reversal of 20621249 is 94212602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20621249 - 2²⁰ = 19572673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20621243) 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, 937319 + ... + 937340.

It is an arithmetic number, because the mean of its divisors is an integer number (5623980).

Almost surely, 2^20621249 is an apocalyptic number.

It is an amenable number.

20621249 is a deficient number, since it is larger than the sum of its proper divisors (1874671).

20621249 is a wasteful number, since it uses less digits than its factorization.

20621249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1874670.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 20621249 is about 4541.0625408598. The cubic root of 20621249 is about 274.2237015556.

The spelling of 20621249 in words is "twenty million, six hundred twenty-one thousand, two hundred forty-nine".