21400433 has 8 divisors (see below), whose sum is σ = 22801248. Its totient is φ = 20015424.

The previous prime is 21400429. The next prime is 21400451. The reversal of 21400433 is 33400412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21400433 - 2² = 21400429 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21400453) 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, 1091 + ... + 6632.

It is an arithmetic number, because the mean of its divisors is an integer number (2850156).

Almost surely, 2^21400433 is an apocalyptic number.

It is an amenable number.

21400433 is a deficient number, since it is larger than the sum of its proper divisors (1400815).

21400433 is a wasteful number, since it uses less digits than its factorization.

21400433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7903.

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 21400433 is about 4626.0602028076. The cubic root of 21400433 is about 277.6349823518.

Adding to 21400433 its reverse (33400412), we get a palindrome (54800845).

The spelling of 21400433 in words is "twenty-one million, four hundred thousand, four hundred thirty-three".