21892123 has 24 divisors (see below), whose sum is σ = 26060400. Its totient is φ = 18221760.

The previous prime is 21892109. The next prime is 21892139. The reversal of 21892123 is 32129812.

It is not a de Polignac number, because 21892123 - 2¹³ = 21883931 is a prime.

It is an alternating number because its digits alternate between even and odd.

Its product of digits (1728) is a multiple of the sum of its prime divisors (216).

It is a junction number, because it is equal to n+sod(n) for n = 21892091 and 21892100.

It is not an unprimeable number, because it can be changed into a prime (21892153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 146853 + ... + 147001.

It is an arithmetic number, because the mean of its divisors is an integer number (1085850).

Almost surely, 2^21892123 is an apocalyptic number.

21892123 is a deficient number, since it is larger than the sum of its proper divisors (4168277).

21892123 is a wasteful number, since it uses less digits than its factorization.

21892123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235 (or 216 counting only the distinct ones).

The product of its digits is 1728, while the sum is 28.

The square root of 21892123 is about 4678.9019010875. The cubic root of 21892123 is about 279.7451891009.

The spelling of 21892123 in words is "twenty-one million, eight hundred ninety-two thousand, one hundred twenty-three".