21861447201 has 12 divisors (see below), whose sum is σ = 34448341200. Its totient is φ = 13249361880.

The previous prime is 21861447199. The next prime is 21861447217. The reversal of 21861447201 is 10274416812.

It is a happy number.

21861447201 is a `hidden beast` number, since 2 + 1 + 8 + 6 + 1 + 447 + 201 = 666.

It is not a de Polignac number, because 21861447201 - 2¹ = 21861447199 is a prime.

It is a super-2 number, since 2×21861447201² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21861447221) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 110411251 + ... + 110411448.

It is an arithmetic number, because the mean of its divisors is an integer number (2870695100).

Almost surely, 2^21861447201 is an apocalyptic number.

It is an amenable number.

21861447201 is a deficient number, since it is larger than the sum of its proper divisors (12586893999).

21861447201 is a wasteful number, since it uses less digits than its factorization.

21861447201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220822716 (or 220822713 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The spelling of 21861447201 in words is "twenty-one billion, eight hundred sixty-one million, four hundred forty-seven thousand, two hundred one".