21141144661 has 32 divisors (see below), whose sum is σ = 26742383360. Its totient is φ = 16266023424.

The previous prime is 21141144643. The next prime is 21141144667. The reversal of 21141144661 is 16644114112.

It is a happy number.

It is not a de Polignac number, because 21141144661 - 2⁷ = 21141144533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21141144667) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 884281 + ... + 907873.

It is an arithmetic number, because the mean of its divisors is an integer number (835699480).

Almost surely, 2^21141144661 is an apocalyptic number.

It is an amenable number.

21141144661 is a deficient number, since it is larger than the sum of its proper divisors (5601238699).

21141144661 is a wasteful number, since it uses less digits than its factorization.

21141144661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23885.

The product of its digits is 4608, while the sum is 31.

Adding to 21141144661 its reverse (16644114112), we get a palindrome (37785258773).

The spelling of 21141144661 in words is "twenty-one billion, one hundred forty-one million, one hundred forty-four thousand, six hundred sixty-one".