21127870 has 16 divisors (see below), whose sum is σ = 38094048. Its totient is φ = 8436960.

The previous prime is 21127859. The next prime is 21127877. The reversal of 21127870 is 7872112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21127877) 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, 6175 + ... + 8965.

It is an arithmetic number, because the mean of its divisors is an integer number (2380878).

Almost surely, 2^21127870 is an apocalyptic number.

21127870 is a deficient number, since it is larger than the sum of its proper divisors (16966178).

21127870 is a wasteful number, since it uses less digits than its factorization.

21127870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3555.

The product of its (nonzero) digits is 1568, while the sum is 28.

The square root of 21127870 is about 4596.5062819494. The cubic root of 21127870 is about 276.4512589208.

Adding to 21127870 its reverse (7872112), we get a palindrome (28999982).

The spelling of 21127870 in words is "twenty-one million, one hundred twenty-seven thousand, eight hundred seventy".