21365880398 has 16 divisors (see below), whose sum is σ = 34051479840. Its totient is φ = 10054527328.

The previous prime is 21365880391. The next prime is 21365880421. The reversal of 21365880398 is 89308856312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21365880391) 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, 1077386 + ... + 1097037.

It is an arithmetic number, because the mean of its divisors is an integer number (2128217490).

Almost surely, 2^21365880398 is an apocalyptic number.

21365880398 is a deficient number, since it is larger than the sum of its proper divisors (12685599442).

21365880398 is an equidigital number, since it uses as much as digits as its factorization.

21365880398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2174476 (or 2174442 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 53.

The spelling of 21365880398 in words is "twenty-one billion, three hundred sixty-five million, eight hundred eighty thousand, three hundred ninety-eight".