21860901 has 16 divisors (see below), whose sum is σ = 32512320. Its totient is φ = 14517360.

The previous prime is 21860897. The next prime is 21860933. The reversal of 21860901 is 10906812.

It is not a de Polignac number, because 21860901 - 2² = 21860897 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21860941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6211 + ... + 9071.

It is an arithmetic number, because the mean of its divisors is an integer number (2032020).

Almost surely, 2^21860901 is an apocalyptic number.

It is an amenable number.

21860901 is a deficient number, since it is larger than the sum of its proper divisors (10651419).

21860901 is a wasteful number, since it uses less digits than its factorization.

21860901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3153 (or 3147 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 21860901 is about 4675.5642440245. The cubic root of 21860901 is about 279.6121372911.

The spelling of 21860901 in words is "twenty-one million, eight hundred sixty thousand, nine hundred one".