215768904820 has 24 divisors (see below), whose sum is σ = 517845371904. Its totient is φ = 73977910176.

The previous prime is 215768904809. The next prime is 215768904829. The reversal of 215768904820 is 28409867512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215768904829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 770603092 + ... + 770603371.

It is an arithmetic number, because the mean of its divisors is an integer number (21576890496).

Almost surely, 2^215768904820 is an apocalyptic number.

215768904820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215768904820 is an abundant number, since it is smaller than the sum of its proper divisors (302076467084).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

215768904820 is a wasteful number, since it uses less digits than its factorization.

215768904820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1541206479 (or 1541206477 counting only the distinct ones).

The product of its (nonzero) digits is 1935360, while the sum is 52.

The spelling of 215768904820 in words is "two hundred fifteen billion, seven hundred sixty-eight million, nine hundred four thousand, eight hundred twenty".