21082781627 has 4 divisors (see below), whose sum is σ = 21088897800. Its totient is φ = 21076665456.

The previous prime is 21082781623. The next prime is 21082781639. The reversal of 21082781627 is 72618728012.

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 21082781627 - 2² = 21082781623 is a prime.

It is a super-2 number, since 2×21082781627² (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 (21082781623) 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, 3052913 + ... + 3059810.

It is an arithmetic number, because the mean of its divisors is an integer number (5272224450).

Almost surely, 2^21082781627 is an apocalyptic number.

21082781627 is a deficient number, since it is larger than the sum of its proper divisors (6116173).

21082781627 is an equidigital number, since it uses as much as digits as its factorization.

21082781627 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6116172.

The product of its (nonzero) digits is 150528, while the sum is 44.

The spelling of 21082781627 in words is "twenty-one billion, eighty-two million, seven hundred eighty-one thousand, six hundred twenty-seven".