212305997887 has 32 divisors (see below), whose sum is σ = 235355258880. Its totient is φ = 190624258560.

The previous prime is 212305997873. The next prime is 212305997947. The reversal of 212305997887 is 788799503212.

It is a de Polignac number, because none of the positive numbers 2^k-212305997887 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212305997807) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20946873 + ... + 20957005.

It is an arithmetic number, because the mean of its divisors is an integer number (7354851840).

Almost surely, 2^212305997887 is an apocalyptic number.

212305997887 is a deficient number, since it is larger than the sum of its proper divisors (23049260993).

212305997887 is a wasteful number, since it uses less digits than its factorization.

212305997887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10743.

The product of its (nonzero) digits is 15240960, while the sum is 61.

The spelling of 212305997887 in words is "two hundred twelve billion, three hundred five million, nine hundred ninety-seven thousand, eight hundred eighty-seven".