21214421397 has 80 divisors (see below), whose sum is σ = 36202541760. Its totient is φ = 12264473088.

The previous prime is 21214421377. The next prime is 21214421399. The reversal of 21214421397 is 79312441212.

21214421397 is a `hidden beast` number, since 2 + 121 + 442 + 1 + 3 + 97 = 666.

It is not a de Polignac number, because 21214421397 - 2²⁰ = 21213372821 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21214421399) 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 79 ways as a sum of consecutive naturals, for example, 18240538 + ... + 18241700.

It is an arithmetic number, because the mean of its divisors is an integer number (452531772).

Almost surely, 2^21214421397 is an apocalyptic number.

21214421397 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

21214421397 is a deficient number, since it is larger than the sum of its proper divisors (14988120363).

21214421397 is a wasteful number, since it uses less digits than its factorization.

21214421397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2224 (or 2215 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The spelling of 21214421397 in words is "twenty-one billion, two hundred fourteen million, four hundred twenty-one thousand, three hundred ninety-seven".