21870699 has 4 divisors (see below), whose sum is σ = 29160936. Its totient is φ = 14580464.

The previous prime is 21870679. The next prime is 21870713. The reversal of 21870699 is 99607812.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21870699 - 2¹⁵ = 21837931 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21870699.

It is not an unprimeable number, because it can be changed into a prime (21870659) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3645114 + ... + 3645119.

It is an arithmetic number, because the mean of its divisors is an integer number (7290234).

Almost surely, 2^21870699 is an apocalyptic number.

21870699 is a deficient number, since it is larger than the sum of its proper divisors (7290237).

21870699 is an equidigital number, since it uses as much as digits as its factorization.

21870699 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7290236.

The product of its (nonzero) digits is 54432, while the sum is 42.

The square root of 21870699 is about 4676.6119146237. The cubic root of 21870699 is about 279.6539048670.

The spelling of 21870699 in words is "twenty-one million, eight hundred seventy thousand, six hundred ninety-nine".