21730817380 has 24 divisors (see below), whose sum is σ = 45637623360. Its totient is φ = 8691773280.

The previous prime is 21730817363. The next prime is 21730817387. The reversal of 21730817380 is 8371803712.

It is not an unprimeable number, because it can be changed into a prime (21730817387) 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 7 ways as a sum of consecutive naturals, for example, 458851 + ... + 503989.

It is an arithmetic number, because the mean of its divisors is an integer number (1901567640).

Almost surely, 2^21730817380 is an apocalyptic number.

21730817380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21730817380 is an abundant number, since it is smaller than the sum of its proper divisors (23906805980).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21730817380 is a wasteful number, since it uses less digits than its factorization.

21730817380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69219 (or 69217 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 40.

The spelling of 21730817380 in words is "twenty-one billion, seven hundred thirty million, eight hundred seventeen thousand, three hundred eighty".