21100220144 has 10 divisors (see below), whose sum is σ = 40881676560. Its totient is φ = 10550110064.

The previous prime is 21100220131. The next prime is 21100220179. The reversal of 21100220144 is 44102200112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 659381864 + ... + 659381895.

It is an arithmetic number, because the mean of its divisors is an integer number (4088167656).

Almost surely, 2^21100220144 is an apocalyptic number.

It is an amenable number.

21100220144 is a deficient number, since it is larger than the sum of its proper divisors (19781456416).

21100220144 is a wasteful number, since it uses less digits than its factorization.

21100220144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1318763767 (or 1318763761 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21100220144 its reverse (44102200112), we get a palindrome (65202420256).

The spelling of 21100220144 in words is "twenty-one billion, one hundred million, two hundred twenty thousand, one hundred forty-four".