21371907399 has 8 divisors (see below), whose sum is σ = 28816055280. Its totient is φ = 14087848896.

The previous prime is 21371907383. The next prime is 21371907407. The reversal of 21371907399 is 99370917312.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21371907399 - 2⁴ = 21371907383 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21371907379) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40022032 + ... + 40022565.

It is an arithmetic number, because the mean of its divisors is an integer number (3602006910).

Almost surely, 2^21371907399 is an apocalyptic number.

21371907399 is a deficient number, since it is larger than the sum of its proper divisors (7444147881).

21371907399 is an equidigital number, since it uses as much as digits as its factorization.

21371907399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80044689.

The product of its (nonzero) digits is 642978, while the sum is 51.

The spelling of 21371907399 in words is "twenty-one billion, three hundred seventy-one million, nine hundred seven thousand, three hundred ninety-nine".