21261170 has 16 divisors (see below), whose sum is σ = 43737408. Its totient is φ = 7289520.

The previous prime is 21261161. The next prime is 21261179. The reversal of 21261170 is 7116212.

It is an interprime number because it is at equal distance from previous prime (21261161) and next prime (21261179).

It is not an unprimeable number, because it can be changed into a prime (21261179) 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, 151796 + ... + 151935.

It is an arithmetic number, because the mean of its divisors is an integer number (2733588).

Almost surely, 2^21261170 is an apocalyptic number.

21261170 is an abundant number, since it is smaller than the sum of its proper divisors (22476238).

21261170 is a wasteful number, since it uses less digits than its factorization.

21261170 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 303745.

The product of its (nonzero) digits is 168, while the sum is 20.

The square root of 21261170 is about 4610.9836260824. The cubic root of 21261170 is about 277.0314360878.

Adding to 21261170 its reverse (7116212), we get a palindrome (28377382).

The spelling of 21261170 in words is "twenty-one million, two hundred sixty-one thousand, one hundred seventy".