16821517450 has 12 divisors (see below), whose sum is σ = 31288022550. Its totient is φ = 6728606960.

The previous prime is 16821517421. The next prime is 16821517457. The reversal of 16821517450 is 5471512861.

It can be written as a sum of positive squares in 3 ways, for example, as 13356193761 + 3465323689 = 115569^2 + 58867^2 .

It is not an unprimeable number, because it can be changed into a prime (16821517457) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 168215125 + ... + 168215224.

Almost surely, 2^16821517450 is an apocalyptic number.

16821517450 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

16821517450 is a deficient number, since it is larger than the sum of its proper divisors (14466505100).

16821517450 is a wasteful number, since it uses less digits than its factorization.

16821517450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336430361 (or 336430356 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 40.

The spelling of 16821517450 in words is "sixteen billion, eight hundred twenty-one million, five hundred seventeen thousand, four hundred fifty".