21872467 has 4 divisors (see below), whose sum is σ = 22626720. Its totient is φ = 21118216.

The previous prime is 21872449. The next prime is 21872483. The reversal of 21872467 is 76427812.

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

It is a cyclic number.

It is not a de Polignac number, because 21872467 - 2¹¹ = 21870419 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21872407) 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, 377083 + ... + 377140.

It is an arithmetic number, because the mean of its divisors is an integer number (5656680).

Almost surely, 2^21872467 is an apocalyptic number.

21872467 is a deficient number, since it is larger than the sum of its proper divisors (754253).

21872467 is an equidigital number, since it uses as much as digits as its factorization.

21872467 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 754252.

The product of its digits is 37632, while the sum is 37.

The square root of 21872467 is about 4676.8009365377. The cubic root of 21872467 is about 279.6614402881.

It can be divided in two parts, 218724 and 67, that added together give a triangular number (218791 = T₆₆₁).

The spelling of 21872467 in words is "twenty-one million, eight hundred seventy-two thousand, four hundred sixty-seven".