20270921 has 4 divisors (see below), whose sum is σ = 22113744. Its totient is φ = 18428100.

The previous prime is 20270911. The next prime is 20270947. The reversal of 20270921 is 12907202.

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 a cyclic number.

It is not a de Polignac number, because 20270921 - 2¹⁴ = 20254537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20270911) 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 3 ways as a sum of consecutive naturals, for example, 921395 + ... + 921416.

It is an arithmetic number, because the mean of its divisors is an integer number (5528436).

Almost surely, 2^20270921 is an apocalyptic number.

It is an amenable number.

20270921 is a deficient number, since it is larger than the sum of its proper divisors (1842823).

20270921 is a wasteful number, since it uses less digits than its factorization.

20270921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1842822.

The product of its (nonzero) digits is 504, while the sum is 23.

The square root of 20270921 is about 4502.3239554701. The cubic root of 20270921 is about 272.6619232348.

The spelling of 20270921 in words is "twenty million, two hundred seventy thousand, nine hundred twenty-one".