21699416 has 8 divisors (see below), whose sum is σ = 40686420. Its totient is φ = 10849704.

The previous prime is 21699409. The next prime is 21699439. The reversal of 21699416 is 61499612.

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 21699416.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1356206 + ... + 1356221.

Almost surely, 2^21699416 is an apocalyptic number.

It is an amenable number.

21699416 is a deficient number, since it is larger than the sum of its proper divisors (18987004).

21699416 is a wasteful number, since it uses less digits than its factorization.

21699416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2712433 (or 2712429 counting only the distinct ones).

The product of its digits is 23328, while the sum is 38.

The square root of 21699416 is about 4658.2631956557. The cubic root of 21699416 is about 278.9219430237.

The spelling of 21699416 in words is "twenty-one million, six hundred ninety-nine thousand, four hundred sixteen".