21015531024340 has 48 divisors (see below), whose sum is σ = 44176079937024. Its totient is φ = 8397937440000.

The previous prime is 21015531024239. The next prime is 21015531024349. The reversal of 21015531024340 is 4342013551012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21015531024349) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 84558937 + ... + 84807103.

It is an arithmetic number, because the mean of its divisors is an integer number (920334998688).

Almost surely, 2^{21015531024340} is an apocalyptic number.

21015531024340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21015531024340 is an abundant number, since it is smaller than the sum of its proper divisors (23160548912684).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21015531024340 is a wasteful number, since it uses less digits than its factorization.

21015531024340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252328 (or 252326 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 31.

Adding to 21015531024340 its reverse (4342013551012), we get a palindrome (25357544575352).

The spelling of 21015531024340 in words is "twenty-one trillion, fifteen billion, five hundred thirty-one million, twenty-four thousand, three hundred forty".