21230120144 has 10 divisors (see below), whose sum is σ = 41133357810. Its totient is φ = 10615060064.

The previous prime is 21230120137. The next prime is 21230120203. The reversal of 21230120144 is 44102103212.

It can be written as a sum of positive squares in only one way, i.e., 21028480144 + 201640000 = 145012^2 + 14200^2 .

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, 663441239 + ... + 663441270.

It is an arithmetic number, because the mean of its divisors is an integer number (4113335781).

Almost surely, 2^21230120144 is an apocalyptic number.

It is an amenable number.

21230120144 is a deficient number, since it is larger than the sum of its proper divisors (19903237666).

21230120144 is a wasteful number, since it uses less digits than its factorization.

21230120144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1326882517 (or 1326882511 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 21230120144 its reverse (44102103212), we get a palindrome (65332223356).

The spelling of 21230120144 in words is "twenty-one billion, two hundred thirty million, one hundred twenty thousand, one hundred forty-four".