20619021 has 4 divisors (see below), whose sum is σ = 27492032. Its totient is φ = 13746012.

The previous prime is 20619013. The next prime is 20619043. The reversal of 20619021 is 12091602.

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 not a de Polignac number, because 20619021 - 2³ = 20619013 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 (20619721) 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, 3436501 + ... + 3436506.

It is an arithmetic number, because the mean of its divisors is an integer number (6873008).

Almost surely, 2^20619021 is an apocalyptic number.

It is an amenable number.

20619021 is a deficient number, since it is larger than the sum of its proper divisors (6873011).

20619021 is an equidigital number, since it uses as much as digits as its factorization.

20619021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6873010.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 20619021 is about 4540.8172171978. The cubic root of 20619021 is about 274.2138251346.

The spelling of 20619021 in words is "twenty million, six hundred nineteen thousand, twenty-one".