21003376 has 20 divisors (see below), whose sum is σ = 40789800. Its totient is φ = 10476992.

The previous prime is 21003373. The next prime is 21003397. The reversal of 21003376 is 67330012.

It is a super-2 number, since 2×21003376² = 882283606794752, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21003371) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6855 + ... + 9433.

It is an arithmetic number, because the mean of its divisors is an integer number (2039490).

Almost surely, 2^21003376 is an apocalyptic number.

It is an amenable number.

21003376 is a deficient number, since it is larger than the sum of its proper divisors (19786424).

21003376 is a wasteful number, since it uses less digits than its factorization.

21003376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3096 (or 3090 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 22.

The square root of 21003376 is about 4582.9440319515. The cubic root of 21003376 is about 275.9072011761.

Adding to 21003376 its reverse (67330012), we get a palindrome (88333388).

It can be divided in two parts, 2100 and 3376, that added together give a square (5476 = 74²).

The spelling of 21003376 in words is "twenty-one million, three thousand, three hundred seventy-six".