21274242 has 64 divisors (see below), whose sum is σ = 50056704. Its totient is φ = 5955840.

The previous prime is 21274237. The next prime is 21274247. The reversal of 21274242 is 24247212.

It is an interprime number because it is at equal distance from previous prime (21274237) and next prime (21274247).

It is not an unprimeable number, because it can be changed into a prime (21274247) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 75033 + ... + 75315.

It is an arithmetic number, because the mean of its divisors is an integer number (782136).

Almost surely, 2^21274242 is an apocalyptic number.

21274242 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21274242, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25028352).

21274242 is an abundant number, since it is smaller than the sum of its proper divisors (28782462).

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

21274242 is a wasteful number, since it uses less digits than its factorization.

21274242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 383.

The product of its digits is 1792, while the sum is 24.

The square root of 21274242 is about 4612.4008932442. The cubic root of 21274242 is about 277.0882001796.

The spelling of 21274242 in words is "twenty-one million, two hundred seventy-four thousand, two hundred forty-two".