21161669 has 8 divisors (see below), whose sum is σ = 21800448. Its totient is φ = 20526480.

The previous prime is 21161653. The next prime is 21161671. The reversal of 21161669 is 96616112.

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 21161669 - 2⁴ = 21161653 is a prime.

It is a super-2 number, since 2×21161669² = 895632469731122, 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 (21161639) 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, 15284 + ... + 16610.

It is an arithmetic number, because the mean of its divisors is an integer number (2725056).

Almost surely, 2^21161669 is an apocalyptic number.

It is an amenable number.

21161669 is a deficient number, since it is larger than the sum of its proper divisors (638779).

21161669 is a wasteful number, since it uses less digits than its factorization.

21161669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1795.

The product of its digits is 3888, while the sum is 32.

The square root of 21161669 is about 4600.1814094664. The cubic root of 21161669 is about 276.5985966632.

The spelling of 21161669 in words is "twenty-one million, one hundred sixty-one thousand, six hundred sixty-nine".