21880801 has 8 divisors (see below), whose sum is σ = 22782824. Its totient is φ = 20995200.

The previous prime is 21880787. The next prime is 21880829. The reversal of 21880801 is 10808812.

It can be written as a sum of positive squares in 4 ways, for example, as 16192576 + 5688225 = 4024^2 + 2385^2 .

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

It is a 3-Lehmer number, since φ(21880801) divides (21880801-1)³.

It is a cyclic number.

It is not a de Polignac number, because 21880801 - 2⁷ = 21880673 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21880801.

It is not an unprimeable number, because it can be changed into a prime (21881801) 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, 1350 + ... + 6751.

It is an arithmetic number, because the mean of its divisors is an integer number (2847853).

It is a Poulet number, since it divides 2^21880800-1.

Almost surely, 2^21880801 is an apocalyptic number.

21880801 is the 2701-st octagonal number.

It is an amenable number.

21880801 is a deficient number, since it is larger than the sum of its proper divisors (902023).

21880801 is an equidigital number, since it uses as much as digits as its factorization.

21880801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8211.

The product of its (nonzero) digits is 1024, while the sum is 28.

The square root of 21880801 is about 4677.6918453442. The cubic root of 21880801 is about 279.6969552955.

The spelling of 21880801 in words is "twenty-one million, eight hundred eighty thousand, eight hundred one".