20601621 has 20 divisors (see below), whose sum is σ = 30979872. Its totient is φ = 13643208.

The previous prime is 20601617. The next prime is 20601667. The reversal of 20601621 is 12610602.

It is a happy number.

20601621 is a `hidden beast` number, since 2 + 0 + 601 + 62 + 1 = 666.

It is not a de Polignac number, because 20601621 - 2² = 20601617 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20601594 and 20601603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20601421) 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 19 ways as a sum of consecutive naturals, for example, 12766 + ... + 14288.

Almost surely, 2^20601621 is an apocalyptic number.

It is an amenable number.

20601621 is a deficient number, since it is larger than the sum of its proper divisors (10378251).

20601621 is a wasteful number, since it uses less digits than its factorization.

20601621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1702 (or 1693 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 20601621 is about 4538.9008581374. The cubic root of 20601621 is about 274.1366688149.

The spelling of 20601621 in words is "twenty million, six hundred one thousand, six hundred twenty-one".