21874369 has 4 divisors (see below), whose sum is σ = 23862960. Its totient is φ = 19885780.

The previous prime is 21874367. The next prime is 21874397. The reversal of 21874369 is 96347812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21874369 - 2¹ = 21874367 is a prime.

It is a super-2 number, since 2×21874369² = 956976038296322, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (21874367) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 994279 + ... + 994300.

It is an arithmetic number, because the mean of its divisors is an integer number (5965740).

Almost surely, 2^21874369 is an apocalyptic number.

It is an amenable number.

21874369 is a deficient number, since it is larger than the sum of its proper divisors (1988591).

21874369 is a wasteful number, since it uses less digits than its factorization.

21874369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1988590.

The product of its digits is 72576, while the sum is 40.

The square root of 21874369 is about 4677.0042762435. The cubic root of 21874369 is about 279.6695463794.

Subtracting from 21874369 its sum of digits (40), we obtain a square (21874329 = 4677²).

It can be divided in two parts, 218743 and 69, that added together give a palindrome (218812).

The spelling of 21874369 in words is "twenty-one million, eight hundred seventy-four thousand, three hundred sixty-nine".