21980569 has 8 divisors (see below), whose sum is σ = 23732352. Its totient is φ = 20237520.

The previous prime is 21980561. The next prime is 21980593. The reversal of 21980569 is 96508912.

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 21980569 - 2³ = 21980561 is a prime.

It is a super-2 number, since 2×21980569² = 966290827127522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21980561) 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, 3642 + ... + 7564.

It is an arithmetic number, because the mean of its divisors is an integer number (2966544).

Almost surely, 2^21980569 is an apocalyptic number.

It is an amenable number.

21980569 is a deficient number, since it is larger than the sum of its proper divisors (1751783).

21980569 is a wasteful number, since it uses less digits than its factorization.

21980569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4367.

The product of its (nonzero) digits is 38880, while the sum is 40.

The square root of 21980569 is about 4688.3439506930. The cubic root of 21980569 is about 280.1214141813.

The spelling of 21980569 in words is "twenty-one million, nine hundred eighty thousand, five hundred sixty-nine".