21232174777 has 16 divisors (see below), whose sum is σ = 24745363200. Its totient is φ = 18013145040.

The previous prime is 21232174751. The next prime is 21232174781. The reversal of 21232174777 is 77747123212.

It is a de Polignac number, because none of the positive numbers 2^k-21232174777 is a prime.

It is a super-2 number, since 2×21232174777² (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 (21232174177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 744127 + ... + 772132.

It is an arithmetic number, because the mean of its divisors is an integer number (1546585200).

Almost surely, 2^21232174777 is an apocalyptic number.

It is an amenable number.

21232174777 is a deficient number, since it is larger than the sum of its proper divisors (3513188423).

21232174777 is a wasteful number, since it uses less digits than its factorization.

21232174777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1516356.

The product of its digits is 230496, while the sum is 43.

Adding to 21232174777 its reverse (77747123212), we get a palindrome (98979297989).

The spelling of 21232174777 in words is "twenty-one billion, two hundred thirty-two million, one hundred seventy-four thousand, seven hundred seventy-seven".