20932921 has 4 divisors (see below), whose sum is σ = 21843072. Its totient is φ = 20022772.

The previous prime is 20932909. The next prime is 20932937. The reversal of 20932921 is 12923902.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12923902 = 2 ⋅6461951.

It is a cyclic number.

It is not a de Polignac number, because 20932921 - 2¹⁷ = 20801849 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20932921.

It is not an unprimeable number, because it can be changed into a prime (20932981) 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, 455041 + ... + 455086.

It is an arithmetic number, because the mean of its divisors is an integer number (5460768).

Almost surely, 2^20932921 is an apocalyptic number.

It is an amenable number.

20932921 is a deficient number, since it is larger than the sum of its proper divisors (910151).

20932921 is an equidigital number, since it uses as much as digits as its factorization.

20932921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 910150.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 20932921 is about 4575.2509220807. The cubic root of 20932921 is about 275.5983489502.

The spelling of 20932921 in words is "twenty million, nine hundred thirty-two thousand, nine hundred twenty-one".