21889877 has 2 divisors, whose sum is σ = 21889878. Its totient is φ = 21889876.

The previous prime is 21889871. The next prime is 21889909. The reversal of 21889877 is 77898812.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21613201 + 276676 = 4649^2 + 526^2 .

It is a cyclic number.

It is not a de Polignac number, because 21889877 - 2¹² = 21885781 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21889871) 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, 10944938 + 10944939.

It is an arithmetic number, because the mean of its divisors is an integer number (10944939).

Almost surely, 2^21889877 is an apocalyptic number.

It is an amenable number.

21889877 is a deficient number, since it is larger than the sum of its proper divisors (1).

21889877 is an equidigital number, since it uses as much as digits as its factorization.

21889877 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 451584, while the sum is 50.

The square root of 21889877 is about 4678.6618813503. The cubic root of 21889877 is about 279.7356220497.

The spelling of 21889877 in words is "twenty-one million, eight hundred eighty-nine thousand, eight hundred seventy-seven".