21553120312 has 8 divisors (see below), whose sum is σ = 40412100600. Its totient is φ = 10776560152.

The previous prime is 21553120271. The next prime is 21553120327. The reversal of 21553120312 is 21302135512.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1347070012 + ... + 1347070027.

It is an arithmetic number, because the mean of its divisors is an integer number (5051512575).

Almost surely, 2^21553120312 is an apocalyptic number.

It is an amenable number.

21553120312 is a deficient number, since it is larger than the sum of its proper divisors (18858980288).

21553120312 is a wasteful number, since it uses less digits than its factorization.

21553120312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2694140045 (or 2694140041 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 25.

Adding to 21553120312 its reverse (21302135512), we get a palindrome (42855255824).

The spelling of 21553120312 in words is "twenty-one billion, five hundred fifty-three million, one hundred twenty thousand, three hundred twelve".