211022209978 has 4 divisors (see below), whose sum is σ = 316533314970. Its totient is φ = 105511104988.

The previous prime is 211022209973. The next prime is 211022209991. The reversal of 211022209978 is 879902220112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 209775908169 + 1246301809 = 458013^2 + 35303^2 .

It is not an unprimeable number, because it can be changed into a prime (211022209973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 52755552493 + ... + 52755552496.

Almost surely, 2^211022209978 is an apocalyptic number.

211022209978 is a deficient number, since it is larger than the sum of its proper divisors (105511104992).

211022209978 is a wasteful number, since it uses less digits than its factorization.

211022209978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105511104991.

The product of its (nonzero) digits is 72576, while the sum is 43.

The spelling of 211022209978 in words is "two hundred eleven billion, twenty-two million, two hundred nine thousand, nine hundred seventy-eight".