21533374 has 4 divisors (see below), whose sum is σ = 32300064. Its totient is φ = 10766686.

The previous prime is 21533363. The next prime is 21533431. The reversal of 21533374 is 47333512.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5383342 + ... + 5383345.

It is an arithmetic number, because the mean of its divisors is an integer number (8075016).

Almost surely, 2^21533374 is an apocalyptic number.

21533374 is a deficient number, since it is larger than the sum of its proper divisors (10766690).

21533374 is a wasteful number, since it uses less digits than its factorization.

21533374 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10766689.

The product of its digits is 7560, while the sum is 28.

The square root of 21533374 is about 4640.4066632139. The cubic root of 21533374 is about 278.2086920459.

Adding to 21533374 its reverse (47333512), we get a palindrome (68866886).

The spelling of 21533374 in words is "twenty-one million, five hundred thirty-three thousand, three hundred seventy-four".