21003662 has 4 divisors (see below), whose sum is σ = 31505496. Its totient is φ = 10501830.

The previous prime is 21003659. The next prime is 21003667. The reversal of 21003662 is 26630012.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21003667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5250914 + ... + 5250917.

It is an arithmetic number, because the mean of its divisors is an integer number (7876374).

Almost surely, 2^21003662 is an apocalyptic number.

21003662 is a deficient number, since it is larger than the sum of its proper divisors (10501834).

21003662 is a wasteful number, since it uses less digits than its factorization.

21003662 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10501833.

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 21003662 is about 4582.9752344956. The cubic root of 21003662 is about 275.9084535002.

Adding to 21003662 its reverse (26630012), we get a palindrome (47633674).

The spelling of 21003662 in words is "twenty-one million, three thousand, six hundred sixty-two".