21891283387 has 16 divisors (see below), whose sum is σ = 22311014400. Its totient is φ = 21475584000.

The previous prime is 21891283369. The next prime is 21891283451. The reversal of 21891283387 is 78338219812.

It is a cyclic number.

It is not a de Polignac number, because 21891283387 - 2⁷ = 21891283259 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21891283787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9724012 + ... + 9726262.

It is an arithmetic number, because the mean of its divisors is an integer number (1394438400).

Almost surely, 2^21891283387 is an apocalyptic number.

21891283387 is a deficient number, since it is larger than the sum of its proper divisors (419731013).

21891283387 is a wasteful number, since it uses less digits than its factorization.

21891283387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3066.

The product of its digits is 1161216, while the sum is 52.

The spelling of 21891283387 in words is "twenty-one billion, eight hundred ninety-one million, two hundred eighty-three thousand, three hundred eighty-seven".