21027793777771 has 24 divisors (see below), whose sum is σ = 23508725688000. Its totient is φ = 18789149636400.

The previous prime is 21027793777769. The next prime is 21027793777777. The reversal of 21027793777771 is 17777739772012.

It is not a de Polignac number, because 21027793777771 - 2¹ = 21027793777769 is a prime.

It is a super-2 number, since 2×21027793777771² (a number of 27 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (67) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21027793777697 and 21027793777706.

It is not an unprimeable number, because it can be changed into a prime (21027793777777) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 44734756 + ... + 45202366.

It is an arithmetic number, because the mean of its divisors is an integer number (979530237000).

Almost surely, 2^{21027793777771} is an apocalyptic number.

21027793777771 is a deficient number, since it is larger than the sum of its proper divisors (2480931910229).

21027793777771 is a wasteful number, since it uses less digits than its factorization.

21027793777771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 473991 (or 473980 counting only the distinct ones).

The product of its (nonzero) digits is 88942644, while the sum is 67.

The spelling of 21027793777771 in words is "twenty-one trillion, twenty-seven billion, seven hundred ninety-three million, seven hundred seventy-seven thousand, seven hundred seventy-one".