21038398 has 16 divisors (see below), whose sum is σ = 33701760. Its totient is φ = 9828000.

The previous prime is 21038393. The next prime is 21038419. The reversal of 21038398 is 89383012.

It is a super-2 number, since 2×21038398² = 885228380812808, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21038393) 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, 4053 + ... + 7648.

It is an arithmetic number, because the mean of its divisors is an integer number (2106360).

Almost surely, 2^21038398 is an apocalyptic number.

21038398 is a deficient number, since it is larger than the sum of its proper divisors (12663362).

21038398 is a wasteful number, since it uses less digits than its factorization.

21038398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11763.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 21038398 is about 4586.7633468493. The cubic root of 21038398 is about 276.0604694923.

It can be divided in two parts, 2103 and 8398, that added together give a palindrome (10501).

The spelling of 21038398 in words is "twenty-one million, thirty-eight thousand, three hundred ninety-eight".