21872901 has 8 divisors (see below), whose sum is σ = 29374240. Its totient is φ = 14476752.

The previous prime is 21872891. The next prime is 21872923. The reversal of 21872901 is 10927812.

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

It is not a de Polignac number, because 21872901 - 2¹¹ = 21870853 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21872951) 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, 25810 + ... + 26643.

It is an arithmetic number, because the mean of its divisors is an integer number (3671780).

Almost surely, 2^21872901 is an apocalyptic number.

It is an amenable number.

21872901 is a deficient number, since it is larger than the sum of its proper divisors (7501339).

21872901 is a wasteful number, since it uses less digits than its factorization.

21872901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52595.

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 21872901 is about 4676.8473355456. The cubic root of 21872901 is about 279.6632899844.

The spelling of 21872901 in words is "twenty-one million, eight hundred seventy-two thousand, nine hundred one".