21350172 has 24 divisors (see below), whose sum is σ = 49912576. Its totient is φ = 7103088.

The previous prime is 21350159. The next prime is 21350201. The reversal of 21350172 is 27105312.

It is a congruent number.

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, 6333 + ... + 9099.

Almost surely, 2^21350172 is an apocalyptic number.

It is an amenable number.

21350172 is an abundant number, since it is smaller than the sum of its proper divisors (28562404).

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

21350172 is a wasteful number, since it uses less digits than its factorization.

21350172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3417 (or 3415 counting only the distinct ones).

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 21350172 is about 4620.6246330989. The cubic root of 21350172 is about 277.4174610459.

Adding to 21350172 its reverse (27105312), we get a palindrome (48455484).

The spelling of 21350172 in words is "twenty-one million, three hundred fifty thousand, one hundred seventy-two".