21861287627 has 4 divisors (see below), whose sum is σ = 21995406120. Its totient is φ = 21727169136.

The previous prime is 21861287611. The next prime is 21861287639. The reversal of 21861287627 is 72678216812.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21861287627 - 2⁴ = 21861287611 is a prime.

It is a super-2 number, since 2×21861287627² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21861287027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67059002 + ... + 67059327.

It is an arithmetic number, because the mean of its divisors is an integer number (5498851530).

Almost surely, 2^21861287627 is an apocalyptic number.

21861287627 is a deficient number, since it is larger than the sum of its proper divisors (134118493).

21861287627 is a wasteful number, since it uses less digits than its factorization.

21861287627 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134118492.

The product of its digits is 903168, while the sum is 50.

The spelling of 21861287627 in words is "twenty-one billion, eight hundred sixty-one million, two hundred eighty-seven thousand, six hundred twenty-seven".