21117370 has 8 divisors (see below), whose sum is σ = 38011284. Its totient is φ = 8446944.

The previous prime is 21117359. The next prime is 21117377. The reversal of 21117370 is 7371112.

It can be written as a sum of positive squares in 2 ways, for example, as 20711601 + 405769 = 4551^2 + 637^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21117377) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1055859 + ... + 1055878.

Almost surely, 2^21117370 is an apocalyptic number.

21117370 is a deficient number, since it is larger than the sum of its proper divisors (16893914).

21117370 is a wasteful number, since it uses less digits than its factorization.

21117370 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2111744.

The product of its (nonzero) digits is 294, while the sum is 22.

The square root of 21117370 is about 4595.3639681749. The cubic root of 21117370 is about 276.4054549785.

Adding to 21117370 its reverse (7371112), we get a palindrome (28488482).

The spelling of 21117370 in words is "twenty-one million, one hundred seventeen thousand, three hundred seventy".