21869929 has 8 divisors (see below), whose sum is σ = 22476960. Its totient is φ = 21267456.

The previous prime is 21869879. The next prime is 21869951. The reversal of 21869929 is 92996812.

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

It is not a de Polignac number, because 21869929 - 2¹⁵ = 21837161 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21869959) 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, 10062 + ... + 12040.

It is an arithmetic number, because the mean of its divisors is an integer number (2809620).

Almost surely, 2^21869929 is an apocalyptic number.

It is an amenable number.

21869929 is a deficient number, since it is larger than the sum of its proper divisors (607031).

21869929 is a wasteful number, since it uses less digits than its factorization.

21869929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2279.

The product of its digits is 139968, while the sum is 46.

The square root of 21869929 is about 4676.5295893429. The cubic root of 21869929 is about 279.6506229107.

The spelling of 21869929 in words is "twenty-one million, eight hundred sixty-nine thousand, nine hundred twenty-nine".