20508621 has 8 divisors (see below), whose sum is σ = 31251264. Its totient is φ = 11719200.

The previous prime is 20508611. The next prime is 20508643. The reversal of 20508621 is 12680502.

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

It is not a de Polignac number, because 20508621 - 2⁷ = 20508493 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20508591 and 20508600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20508601) 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, 488280 + ... + 488321.

It is an arithmetic number, because the mean of its divisors is an integer number (3906408).

Almost surely, 2^20508621 is an apocalyptic number.

20508621 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20508621 is a deficient number, since it is larger than the sum of its proper divisors (10742643).

20508621 is an equidigital number, since it uses as much as digits as its factorization.

20508621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 976611.

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 20508621 is about 4528.6444991852. The cubic root of 20508621 is about 273.7235432408.

The spelling of 20508621 in words is "twenty million, five hundred eight thousand, six hundred twenty-one".