21077899 has 2 divisors, whose sum is σ = 21077900. Its totient is φ = 21077898.

The previous prime is 21077891. The next prime is 21077929. The reversal of 21077899 is 99877012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21077899 - 2³ = 21077891 is a prime.

It is not a weakly prime, because it can be changed into another prime (21077891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10538949 + 10538950.

It is an arithmetic number, because the mean of its divisors is an integer number (10538950).

Almost surely, 2^21077899 is an apocalyptic number.

21077899 is a deficient number, since it is larger than the sum of its proper divisors (1).

21077899 is an equidigital number, since it uses as much as digits as its factorization.

21077899 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 63504, while the sum is 43.

The square root of 21077899 is about 4591.0673051046. The cubic root of 21077899 is about 276.2331354746.

The spelling of 21077899 in words is "twenty-one million, seventy-seven thousand, eight hundred ninety-nine".