21177034212 has 96 divisors (see below), whose sum is σ = 54557153280. Its totient is φ = 6368181120.

The previous prime is 21177034187. The next prime is 21177034213. The reversal of 21177034212 is 21243077112.

It is a self number, because there is not a number n which added to its sum of digits gives 21177034212.

It is not an unprimeable number, because it can be changed into a prime (21177034213) 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, 369787 + ... + 423197.

It is an arithmetic number, because the mean of its divisors is an integer number (568303680).

Almost surely, 2^21177034212 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21177034212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27278576640).

21177034212 is an abundant number, since it is smaller than the sum of its proper divisors (33380119068).

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

21177034212 is a wasteful number, since it uses less digits than its factorization.

21177034212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53521 (or 53519 counting only the distinct ones).

The product of its (nonzero) digits is 4704, while the sum is 30.

The spelling of 21177034212 in words is "twenty-one billion, one hundred seventy-seven million, thirty-four thousand, two hundred twelve".