21502543400144 has 40 divisors (see below), whose sum is σ = 41675288503680. Its totient is φ = 10747630869248.

The previous prime is 21502543400119. The next prime is 21502543400147. The reversal of 21502543400144 is 44100434520512.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21502543400147) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1059385004 + ... + 1059405300.

It is an arithmetic number, because the mean of its divisors is an integer number (1041882212592).

Almost surely, 2^{21502543400144} is an apocalyptic number.

It is an amenable number.

21502543400144 is a deficient number, since it is larger than the sum of its proper divisors (20172745103536).

21502543400144 is a wasteful number, since it uses less digits than its factorization.

21502543400144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39467 (or 39461 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 35.

Adding to 21502543400144 its reverse (44100434520512), we get a palindrome (65602977920656).

The spelling of 21502543400144 in words is "twenty-one trillion, five hundred two billion, five hundred forty-three million, four hundred thousand, one hundred forty-four".