211521510340 has 24 divisors (see below), whose sum is σ = 507651625152. Its totient is φ = 72521660640.

The previous prime is 211521510301. The next prime is 211521510377. The reversal of 211521510340 is 43015125112.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 755433826 + ... + 755434105.

It is an arithmetic number, because the mean of its divisors is an integer number (21152151048).

Almost surely, 2^211521510340 is an apocalyptic number.

211521510340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

211521510340 is an abundant number, since it is smaller than the sum of its proper divisors (296130114812).

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

211521510340 is a wasteful number, since it uses less digits than its factorization.

211521510340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1510867947 (or 1510867945 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 25.

Adding to 211521510340 its reverse (43015125112), we get a palindrome (254536635452).

The spelling of 211521510340 in words is "two hundred eleven billion, five hundred twenty-one million, five hundred ten thousand, three hundred forty".