21419887 has 2 divisors, whose sum is σ = 21419888. Its totient is φ = 21419886.

The previous prime is 21419857. The next prime is 21419899. The reversal of 21419887 is 78891412.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21419887 - 2⁷ = 21419759 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21419807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10709943 + 10709944.

It is an arithmetic number, because the mean of its divisors is an integer number (10709944).

Almost surely, 2^21419887 is an apocalyptic number.

21419887 is a deficient number, since it is larger than the sum of its proper divisors (1).

21419887 is an equidigital number, since it uses as much as digits as its factorization.

21419887 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32256, while the sum is 40.

The square root of 21419887 is about 4628.1623783096. The cubic root of 21419887 is about 277.7190846245.

The spelling of 21419887 in words is "twenty-one million, four hundred nineteen thousand, eight hundred eighty-seven".