87991211212 has 12 divisors (see below), whose sum is σ = 155479616656. Its totient is φ = 43568463600.

The previous prime is 87991211171. The next prime is 87991211227. The reversal of 87991211212 is 21211219978.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106785039 + ... + 106785862.

Almost surely, 2^87991211212 is an apocalyptic number.

It is an amenable number.

87991211212 is a deficient number, since it is larger than the sum of its proper divisors (67488405444).

87991211212 is a wasteful number, since it uses less digits than its factorization.

87991211212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213571008 (or 213571006 counting only the distinct ones).

The product of its digits is 36288, while the sum is 43.

The spelling of 87991211212 in words is "eighty-seven billion, nine hundred ninety-one million, two hundred eleven thousand, two hundred twelve".