20021123 has 4 divisors (see below), whose sum is σ = 20174088. Its totient is φ = 19868160.

The previous prime is 20021093. The next prime is 20021137. The reversal of 20021123 is 32112002.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20021123 - 2⁶ = 20021059 is a prime.

It is a super-2 number, since 2×20021123² = 801690732362258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20021153) 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, 76286 + ... + 76547.

It is an arithmetic number, because the mean of its divisors is an integer number (5043522).

Almost surely, 2^20021123 is an apocalyptic number.

20021123 is a deficient number, since it is larger than the sum of its proper divisors (152965).

20021123 is a wasteful number, since it uses less digits than its factorization.

20021123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152964.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 20021123 is about 4474.4969549660. The cubic root of 20021123 is about 271.5372891091.

Adding to 20021123 its reverse (32112002), we get a palindrome (52133125).

It can be divided in two parts, 2002 and 1123, that added together give a 5-th power (3125 = 5⁵).

The spelling of 20021123 in words is "twenty million, twenty-one thousand, one hundred twenty-three".