21699942 has 16 divisors (see below), whose sum is σ = 47345472. Its totient is φ = 6575720.

The previous prime is 21699901. The next prime is 21700001. The reversal of 21699942 is 24999612.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 21699894 and 21699903.

It is a congruent number.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 164328 + ... + 164459.

It is an arithmetic number, because the mean of its divisors is an integer number (2959092).

Almost surely, 2^21699942 is an apocalyptic number.

21699942 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21699942 is an abundant number, since it is smaller than the sum of its proper divisors (25645530).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21699942 is a wasteful number, since it uses less digits than its factorization.

21699942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 328803.

The product of its digits is 69984, while the sum is 42.

The square root of 21699942 is about 4658.3196541242. The cubic root of 21699942 is about 278.9241967212.

The spelling of 21699942 in words is "twenty-one million, six hundred ninety-nine thousand, nine hundred forty-two".