212787640821 has 16 divisors (see below), whose sum is σ = 324283979264. Its totient is φ = 121579383024.

The previous prime is 212787640801. The next prime is 212787640831. The reversal of 212787640821 is 128046787212.

It is not a de Polignac number, because 212787640821 - 2⁵ = 212787640789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212787640801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 370351 + ... + 750156.

It is an arithmetic number, because the mean of its divisors is an integer number (20267748704).

Almost surely, 2^212787640821 is an apocalyptic number.

212787640821 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

212787640821 is a deficient number, since it is larger than the sum of its proper divisors (111496338443).

212787640821 is a wasteful number, since it uses less digits than its factorization.

212787640821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1129560.

The product of its (nonzero) digits is 602112, while the sum is 48.

The spelling of 212787640821 in words is "two hundred twelve billion, seven hundred eighty-seven million, six hundred forty thousand, eight hundred twenty-one".