21235777772 has 48 divisors (see below), whose sum is σ = 40746620544. Its totient is φ = 9603792000.

The previous prime is 21235777763. The next prime is 21235777793. The reversal of 21235777772 is 27777753212.

It is a self number, because there is not a number n which added to its sum of digits gives 21235777772.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16074872 + ... + 16076192.

It is an arithmetic number, because the mean of its divisors is an integer number (848887928).

Almost surely, 2^21235777772 is an apocalyptic number.

21235777772 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21235777772 is a deficient number, since it is larger than the sum of its proper divisors (19510842772).

21235777772 is a wasteful number, since it uses less digits than its factorization.

21235777772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2910 (or 2908 counting only the distinct ones).

The product of its digits is 2016840, while the sum is 50.

The spelling of 21235777772 in words is "twenty-one billion, two hundred thirty-five million, seven hundred seventy-seven thousand, seven hundred seventy-two".