21095428 has 6 divisors (see below), whose sum is σ = 36917006. Its totient is φ = 10547712.

The previous prime is 21095423. The next prime is 21095429. The reversal of 21095428 is 82459012.

It can be written as a sum of positive squares in only one way, i.e., 11410884 + 9684544 = 3378^2 + 3112^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21095428.

It is not an unprimeable number, because it can be changed into a prime (21095423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2636925 + ... + 2636932.

Almost surely, 2^21095428 is an apocalyptic number.

It is an amenable number.

21095428 is a deficient number, since it is larger than the sum of its proper divisors (15821578).

21095428 is a wasteful number, since it uses less digits than its factorization.

21095428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5273861 (or 5273859 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 21095428 is about 4592.9759415873. The cubic root of 21095428 is about 276.3096887873.

The spelling of 21095428 in words is "twenty-one million, ninety-five thousand, four hundred twenty-eight".