211921972434 has 32 divisors (see below), whose sum is σ = 475509939840. Its totient is φ = 69954824016.

The previous prime is 211921972403. The next prime is 211921972447. The reversal of 211921972434 is 434279129112.

211921972434 is a `hidden beast` number, since 21 + 1 + 9 + 2 + 197 + 2 + 434 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 211921972434.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19045317 + ... + 19056440.

It is an arithmetic number, because the mean of its divisors is an integer number (14859685620).

Almost surely, 2^211921972434 is an apocalyptic number.

211921972434 is an abundant number, since it is smaller than the sum of its proper divisors (263587967406).

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

211921972434 is a wasteful number, since it uses less digits than its factorization.

211921972434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38101871 (or 38101865 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The spelling of 211921972434 in words is "two hundred eleven billion, nine hundred twenty-one million, nine hundred seventy-two thousand, four hundred thirty-four".