21533274 has 24 divisors (see below), whose sum is σ = 53320800. Its totient is φ = 6152328.

The previous prime is 21533269. The next prime is 21533279. The reversal of 21533274 is 47233512.

It is an interprime number because it is at equal distance from previous prime (21533269) and next prime (21533279).

It is not an unprimeable number, because it can be changed into a prime (21533279) 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, 85324 + ... + 85575.

It is an arithmetic number, because the mean of its divisors is an integer number (2221700).

Almost surely, 2^21533274 is an apocalyptic number.

21533274 is an abundant number, since it is smaller than the sum of its proper divisors (31787526).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21533274 is a wasteful number, since it uses less digits than its factorization.

21533274 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170914 (or 170911 counting only the distinct ones).

The product of its digits is 5040, while the sum is 27.

The square root of 21533274 is about 4640.3958882837. The cubic root of 21533274 is about 278.2082613825.

Adding to 21533274 its reverse (47233512), we get a palindrome (68766786).

It can be divided in two parts, 215 and 33274, that added together give a square (33489 = 183²).

The spelling of 21533274 in words is "twenty-one million, five hundred thirty-three thousand, two hundred seventy-four".