21889963 has 2 divisors, whose sum is σ = 21889964. Its totient is φ = 21889962.

The previous prime is 21889949. The next prime is 21889981. The reversal of 21889963 is 36998812.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21889963 is a prime.

It is not a weakly prime, because it can be changed into another prime (21889943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10944981 + 10944982.

It is an arithmetic number, because the mean of its divisors is an integer number (10944982).

Almost surely, 2^21889963 is an apocalyptic number.

21889963 is a deficient number, since it is larger than the sum of its proper divisors (1).

21889963 is an equidigital number, since it uses as much as digits as its factorization.

21889963 is an evil number, because the sum of its binary digits is even.

The product of its digits is 186624, while the sum is 46.

The square root of 21889963 is about 4678.6710720032. The cubic root of 21889963 is about 279.7359883870.

The spelling of 21889963 in words is "twenty-one million, eight hundred eighty-nine thousand, nine hundred sixty-three".