21727017642 has 32 divisors (see below), whose sum is σ = 47473104384. Its totient is φ = 6574402800.

The previous prime is 21727017593. The next prime is 21727017659. The reversal of 21727017642 is 24671072712.

It is a self number, because there is not a number n which added to its sum of digits gives 21727017642.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 192598 + ... + 283809.

It is an arithmetic number, because the mean of its divisors is an integer number (1483534512).

Almost surely, 2^21727017642 is an apocalyptic number.

21727017642 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21727017642 is an abundant number, since it is smaller than the sum of its proper divisors (25746086742).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21727017642 is a wasteful number, since it uses less digits than its factorization.

21727017642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 477114.

The product of its (nonzero) digits is 65856, while the sum is 39.

The spelling of 21727017642 in words is "twenty-one billion, seven hundred twenty-seven million, seventeen thousand, six hundred forty-two".