21402999 has 6 divisors (see below), whose sum is σ = 30915456. Its totient is φ = 14268660.

The previous prime is 21402977. The next prime is 21403013. The reversal of 21402999 is 99920412.

It is not a de Polignac number, because 21402999 - 2⁵ = 21402967 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21402919) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1189047 + ... + 1189064.

It is an arithmetic number, because the mean of its divisors is an integer number (5152576).

Almost surely, 2^21402999 is an apocalyptic number.

21402999 is a deficient number, since it is larger than the sum of its proper divisors (9512457).

21402999 is a wasteful number, since it uses less digits than its factorization.

21402999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2378117 (or 2378114 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 21402999 is about 4626.3375363240. The cubic root of 21402999 is about 277.6460784341.

The spelling of 21402999 in words is "twenty-one million, four hundred two thousand, nine hundred ninety-nine".