211221954940 has 24 divisors (see below), whose sum is σ = 444043610640. Its totient is φ = 84397828608.

The previous prime is 211221954899. The next prime is 211221954947. The reversal of 211221954940 is 49459122112.

It is a super-2 number, since 2×211221954940² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 211221954893 and 211221954902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211221954947) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5665542 + ... + 5702701.

It is an arithmetic number, because the mean of its divisors is an integer number (18501817110).

Almost surely, 2^211221954940 is an apocalyptic number.

211221954940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

211221954940 is an abundant number, since it is smaller than the sum of its proper divisors (232821655700).

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

211221954940 is a wasteful number, since it uses less digits than its factorization.

211221954940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11369181 (or 11369179 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 40.

The spelling of 211221954940 in words is "two hundred eleven billion, two hundred twenty-one million, nine hundred fifty-four thousand, nine hundred forty".