21874237 has 12 divisors (see below), whose sum is σ = 27759456. Its totient is φ = 17044440.

The previous prime is 21874199. The next prime is 21874241. The reversal of 21874237 is 73247812.

It is a de Polignac number, because none of the positive numbers 2^k-21874237 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21874267) 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, 19753 + ... + 20830.

It is an arithmetic number, because the mean of its divisors is an integer number (2313288).

Almost surely, 2^21874237 is an apocalyptic number.

It is an amenable number.

21874237 is a deficient number, since it is larger than the sum of its proper divisors (5885219).

21874237 is a wasteful number, since it uses less digits than its factorization.

21874237 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40608 (or 40601 counting only the distinct ones).

The product of its digits is 18816, while the sum is 34.

The square root of 21874237 is about 4676.9901646251. The cubic root of 21874237 is about 279.6689838267.

The spelling of 21874237 in words is "twenty-one million, eight hundred seventy-four thousand, two hundred thirty-seven".