21025042144 has 48 divisors (see below), whose sum is σ = 41925340800. Its totient is φ = 10378191744.

The previous prime is 21025042123. The next prime is 21025042153. The reversal of 21025042144 is 44124052012.

It is a super-2 number, since 2×21025042144² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 782989 + ... + 809395.

It is an arithmetic number, because the mean of its divisors is an integer number (873444600).

Almost surely, 2^21025042144 is an apocalyptic number.

It is an amenable number.

21025042144 is a deficient number, since it is larger than the sum of its proper divisors (20900298656).

21025042144 is a wasteful number, since it uses less digits than its factorization.

21025042144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26735 (or 26727 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 25.

Adding to 21025042144 its reverse (44124052012), we get a palindrome (65149094156).

The spelling of 21025042144 in words is "twenty-one billion, twenty-five million, forty-two thousand, one hundred forty-four".