21699471 has 8 divisors (see below), whose sum is σ = 28957824. Its totient is φ = 14453720.

The previous prime is 21699449. The next prime is 21699481. The reversal of 21699471 is 17499612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21699471 - 2⁵ = 21699439 is a prime.

It is a super-3 number, since 3×21699471³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21699401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2140 + ... + 6926.

It is an arithmetic number, because the mean of its divisors is an integer number (3619728).

Almost surely, 2^21699471 is an apocalyptic number.

21699471 is a deficient number, since it is larger than the sum of its proper divisors (7258353).

21699471 is a wasteful number, since it uses less digits than its factorization.

21699471 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6301.

The product of its digits is 27216, while the sum is 39.

The square root of 21699471 is about 4658.2690991397. The cubic root of 21699471 is about 278.9221786782.

The spelling of 21699471 in words is "twenty-one million, six hundred ninety-nine thousand, four hundred seventy-one".