21477796771 has 2 divisors, whose sum is σ = 21477796772. Its totient is φ = 21477796770.

The previous prime is 21477796729. The next prime is 21477796789. The reversal of 21477796771 is 17769777412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21477796771 - 2³³ = 12887862179 is a prime.

It is a super-2 number, since 2×21477796771² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21477794771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10738898385 + 10738898386.

It is an arithmetic number, because the mean of its divisors is an integer number (10738898386).

Almost surely, 2^21477796771 is an apocalyptic number.

21477796771 is a deficient number, since it is larger than the sum of its proper divisors (1).

21477796771 is an equidigital number, since it uses as much as digits as its factorization.

21477796771 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7260624, while the sum is 58.

The spelling of 21477796771 in words is "twenty-one billion, four hundred seventy-seven million, seven hundred ninety-six thousand, seven hundred seventy-one".