21698465 has 16 divisors (see below), whose sum is σ = 27258768. Its totient is φ = 16563456.

The previous prime is 21698449. The next prime is 21698473. The reversal of 21698465 is 56489612.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 7349521 + 14348944 = 2711^2 + 3788^2 .

It is a cyclic number.

It is not a de Polignac number, because 21698465 - 2⁴ = 21698449 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8699 + ... + 10911.

It is an arithmetic number, because the mean of its divisors is an integer number (1703673).

Almost surely, 2^21698465 is an apocalyptic number.

It is an amenable number.

21698465 is a deficient number, since it is larger than the sum of its proper divisors (5560303).

21698465 is a wasteful number, since it uses less digits than its factorization.

21698465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2308.

The product of its digits is 103680, while the sum is 41.

The square root of 21698465 is about 4658.1611178661. The cubic root of 21698465 is about 278.9178682805.

The spelling of 21698465 in words is "twenty-one million, six hundred ninety-eight thousand, four hundred sixty-five".