21889019 has 2 divisors, whose sum is σ = 21889020. Its totient is φ = 21889018.

The previous prime is 21889003. The next prime is 21889061. The reversal of 21889019 is 91098812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21889019 - 2⁴ = 21889003 is a prime.

It is a super-2 number, since 2×21889019² = 958258305564722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21889079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10944509 + 10944510.

It is an arithmetic number, because the mean of its divisors is an integer number (10944510).

Almost surely, 2^21889019 is an apocalyptic number.

21889019 is a deficient number, since it is larger than the sum of its proper divisors (1).

21889019 is an equidigital number, since it uses as much as digits as its factorization.

21889019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 38.

The square root of 21889019 is about 4678.5701875680. The cubic root of 21889019 is about 279.7319671441.

The spelling of 21889019 in words is "twenty-one million, eight hundred eighty-nine thousand, nineteen".