21387880371830 has 32 divisors (see below), whose sum is σ = 45515095179840. Its totient is φ = 7080125915520.

The previous prime is 21387880371827. The next prime is 21387880371839. The reversal of 21387880371830 is 3817308878312.

It is a self number, because there is not a number n which added to its sum of digits gives 21387880371830.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21387880371839) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5267948801 + ... + 5267952860.

It is an arithmetic number, because the mean of its divisors is an integer number (1422346724370).

Almost surely, 2^{21387880371830} is an apocalyptic number.

21387880371830 is an abundant number, since it is smaller than the sum of its proper divisors (24127214808010).

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

21387880371830 is a wasteful number, since it uses less digits than its factorization.

21387880371830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10535901704.

The product of its (nonzero) digits is 10838016, while the sum is 59.

The spelling of 21387880371830 in words is "twenty-one trillion, three hundred eighty-seven billion, eight hundred eighty million, three hundred seventy-one thousand, eight hundred thirty".