21003669 has 12 divisors (see below), whose sum is σ = 31658016. Its totient is φ = 13393512.

The previous prime is 21003667. The next prime is 21003673. The reversal of 21003669 is 96630012.

It is a happy number.

It is not a de Polignac number, because 21003669 - 2¹ = 21003667 is a prime.

It is a super-2 number, since 2×21003669² = 882308222923122, which contains 22 as substring.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

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 in 11 ways as a sum of consecutive naturals, for example, 50527 + ... + 50940.

It is an arithmetic number, because the mean of its divisors is an integer number (2638168).

Almost surely, 2^21003669 is an apocalyptic number.

It is an amenable number.

21003669 is a deficient number, since it is larger than the sum of its proper divisors (10654347).

21003669 is a wasteful number, since it uses less digits than its factorization.

21003669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101496 (or 101493 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 21003669 is about 4582.9759981916. The cubic root of 21003669 is about 275.9084841514.

The spelling of 21003669 in words is "twenty-one million, three thousand, six hundred sixty-nine".