78900021212 has 6 divisors (see below), whose sum is σ = 138075037128. Its totient is φ = 39450010604.

The previous prime is 78900021209. The next prime is 78900021217. The reversal of 78900021212 is 21212000987.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78900021217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9862502648 + ... + 9862502655.

It is an arithmetic number, because the mean of its divisors is an integer number (23012506188).

Almost surely, 2^78900021212 is an apocalyptic number.

It is an amenable number.

78900021212 is a deficient number, since it is larger than the sum of its proper divisors (59175015916).

78900021212 is a wasteful number, since it uses less digits than its factorization.

78900021212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19725005307 (or 19725005305 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 32.

The spelling of 78900021212 in words is "seventy-eight billion, nine hundred million, twenty-one thousand, two hundred twelve".