20621039 has 4 divisors (see below), whose sum is σ = 20636040. Its totient is φ = 20606040.

The previous prime is 20621009. The next prime is 20621063. The reversal of 20621039 is 93012602.

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

It is a cyclic number.

It is not a de Polignac number, because 20621039 - 2⁸ = 20620783 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 (20621009) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5204 + ... + 8265.

It is an arithmetic number, because the mean of its divisors is an integer number (5159010).

Almost surely, 2^20621039 is an apocalyptic number.

20621039 is a deficient number, since it is larger than the sum of its proper divisors (15001).

20621039 is a wasteful number, since it uses less digits than its factorization.

20621039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15000.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 20621039 is about 4541.0394184592. The cubic root of 20621039 is about 274.2227706845. Note that the first 3 decimals are identical.

The spelling of 20621039 in words is "twenty million, six hundred twenty-one thousand, thirty-nine".