211642653858 has 24 divisors (see below), whose sum is σ = 449649102192. Its totient is φ = 66397694784.

The previous prime is 211642653853. The next prime is 211642653877. The reversal of 211642653858 is 858356246112.

It is a super-2 number, since 2×211642653858² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 211642653858.

It is not an unprimeable number, because it can be changed into a prime (211642653853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 61025560 + ... + 61029027.

It is an arithmetic number, because the mean of its divisors is an integer number (18735379258).

Almost surely, 2^211642653858 is an apocalyptic number.

211642653858 is an abundant number, since it is smaller than the sum of its proper divisors (238006448334).

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

211642653858 is a wasteful number, since it uses less digits than its factorization.

211642653858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122054626 (or 122054609 counting only the distinct ones).

The product of its digits is 2764800, while the sum is 51.

The spelling of 211642653858 in words is "two hundred eleven billion, six hundred forty-two million, six hundred fifty-three thousand, eight hundred fifty-eight".