21128958379 has 8 divisors (see below), whose sum is σ = 22242361680. Its totient is φ = 20015690400.

The previous prime is 21128958371. The next prime is 21128958391. The reversal of 21128958379 is 97385982112.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21128958379 - 2³ = 21128958371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21128958371) 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, 515709 + ... + 555169.

It is an arithmetic number, because the mean of its divisors is an integer number (2780295210).

Almost surely, 2^21128958379 is an apocalyptic number.

21128958379 is a deficient number, since it is larger than the sum of its proper divisors (1113403301).

21128958379 is a wasteful number, since it uses less digits than its factorization.

21128958379 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67661.

The product of its digits is 2177280, while the sum is 55.

The spelling of 21128958379 in words is "twenty-one billion, one hundred twenty-eight million, nine hundred fifty-eight thousand, three hundred seventy-nine".