21800069 has 8 divisors (see below), whose sum is σ = 23646168. Its totient is φ = 20016640.

The previous prime is 21800059. The next prime is 21800081. The reversal of 21800069 is 96000812.

It can be written as a sum of positive squares in 4 ways, for example, as 1890625 + 19909444 = 1375^2 + 4462^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21800069 is a prime.

It is a super-2 number, since 2×21800069² = 950486016809522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21800039) 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, 14942 + ... + 16335.

It is an arithmetic number, because the mean of its divisors is an integer number (2955771).

Almost surely, 2^21800069 is an apocalyptic number.

It is an amenable number.

21800069 is a deficient number, since it is larger than the sum of its proper divisors (1846099).

21800069 is a wasteful number, since it uses less digits than its factorization.

21800069 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31335.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 21800069 is about 4669.0544010538. The cubic root of 21800069 is about 279.3525388539.

The spelling of 21800069 in words is "twenty-one million, eight hundred thousand, sixty-nine".