21446397 has 32 divisors (see below), whose sum is σ = 37013760. Its totient is φ = 12018240.

The previous prime is 21446387. The next prime is 21446407. The reversal of 21446397 is 79364412.

21446397 is a `hidden beast` number, since 2 + 14 + 4 + 639 + 7 = 666.

It is an interprime number because it is at equal distance from previous prime (21446387) and next prime (21446407).

It is not a de Polignac number, because 21446397 - 2¹⁰ = 21445373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21446317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8947 + ... + 11087.

It is an arithmetic number, because the mean of its divisors is an integer number (1156680).

Almost surely, 2^21446397 is an apocalyptic number.

21446397 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

21446397 is a deficient number, since it is larger than the sum of its proper divisors (15567363).

21446397 is a wasteful number, since it uses less digits than its factorization.

21446397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2210 (or 2204 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 21446397 is about 4631.0254803877. The cubic root of 21446397 is about 277.8336090028.

The spelling of 21446397 in words is "twenty-one million, four hundred forty-six thousand, three hundred ninety-seven".