21333969 has 16 divisors (see below), whose sum is σ = 31824000. Its totient is φ = 14124528.

The previous prime is 21333967. The next prime is 21333971. The reversal of 21333969 is 96933312.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21333967) and next prime (21333971).

It is not a de Polignac number, because 21333969 - 2¹ = 21333967 is a prime.

It is a super-2 number, since 2×21333969² = 910276466585922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21333967) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1372 + ... + 6674.

It is an arithmetic number, because the mean of its divisors is an integer number (1989000).

Almost surely, 2^21333969 is an apocalyptic number.

It is an amenable number.

21333969 is a deficient number, since it is larger than the sum of its proper divisors (10490031).

21333969 is a wasteful number, since it uses less digits than its factorization.

21333969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5461 (or 5455 counting only the distinct ones).

The product of its digits is 26244, while the sum is 36.

The square root of 21333969 is about 4618.8709659396. The cubic root of 21333969 is about 277.3472643795.

The spelling of 21333969 in words is "twenty-one million, three hundred thirty-three thousand, nine hundred sixty-nine".