21374287 has 12 divisors (see below), whose sum is σ = 24878448. Its totient is φ = 18286400.

The previous prime is 21374281. The next prime is 21374293. The reversal of 21374287 is 78247312.

It is an interprime number because it is at equal distance from previous prime (21374281) and next prime (21374293).

It is not a de Polignac number, because 21374287 - 2³ = 21374279 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 (21374281) 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, 3139 + ... + 7252.

It is an arithmetic number, because the mean of its divisors is an integer number (2073204).

Almost surely, 2^21374287 is an apocalyptic number.

21374287 is a deficient number, since it is larger than the sum of its proper divisors (3504161).

21374287 is a wasteful number, since it uses less digits than its factorization.

21374287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10430 (or 10419 counting only the distinct ones).

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

The square root of 21374287 is about 4623.2333923348. The cubic root of 21374287 is about 277.5218693367.

The spelling of 21374287 in words is "twenty-one million, three hundred seventy-four thousand, two hundred eighty-seven".