21003086 has 16 divisors (see below), whose sum is σ = 34083504. Its totient is φ = 9649344.

The previous prime is 21003083. The next prime is 21003097. The reversal of 21003086 is 68030012.

It is a super-2 number, since 2×21003086² = 882259243046792, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21003083) 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, 4325 + ... + 7791.

It is an arithmetic number, because the mean of its divisors is an integer number (2130219).

Almost surely, 2^21003086 is an apocalyptic number.

21003086 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21003086 is a deficient number, since it is larger than the sum of its proper divisors (13080418).

21003086 is a wasteful number, since it uses less digits than its factorization.

21003086 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3715.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 21003086 is about 4582.9123927913. The cubic root of 21003086 is about 275.9059313254.

Adding to 21003086 its reverse (68030012), we get a palindrome (89033098).

The spelling of 21003086 in words is "twenty-one million, three thousand, eighty-six".