21181100370 has 32 divisors (see below), whose sum is σ = 51916232448. Its totient is φ = 5528116608.

The previous prime is 21181100341. The next prime is 21181100419. The reversal of 21181100370 is 7300118112.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21181100370.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7509619 + ... + 7512438.

It is an arithmetic number, because the mean of its divisors is an integer number (1622382264).

Almost surely, 2^21181100370 is an apocalyptic number.

21181100370 is an abundant number, since it is smaller than the sum of its proper divisors (30735132078).

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

21181100370 is a wasteful number, since it uses less digits than its factorization.

21181100370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15022114.

The product of its (nonzero) digits is 336, while the sum is 24.

Adding to 21181100370 its reverse (7300118112), we get a palindrome (28481218482).

The spelling of 21181100370 in words is "twenty-one billion, one hundred eighty-one million, one hundred thousand, three hundred seventy".