21892139 has 2 divisors, whose sum is σ = 21892140. Its totient is φ = 21892138.

The previous prime is 21892109. The next prime is 21892147. The reversal of 21892139 is 93129812.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21892139 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21892099 and 21892108.

It is not a weakly prime, because it can be changed into another prime (21892109) 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 as a sum of consecutive naturals, namely, 10946069 + 10946070.

It is an arithmetic number, because the mean of its divisors is an integer number (10946070).

Almost surely, 2^21892139 is an apocalyptic number.

21892139 is a deficient number, since it is larger than the sum of its proper divisors (1).

21892139 is an equidigital number, since it uses as much as digits as its factorization.

21892139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 35.

The square root of 21892139 is about 4678.9036108901. The cubic root of 21892139 is about 279.7452572521.

The spelling of 21892139 in words is "twenty-one million, eight hundred ninety-two thousand, one hundred thirty-nine".