21013251040 has 48 divisors (see below), whose sum is σ = 49653302832. Its totient is φ = 8403692544.

The previous prime is 21013251037. The next prime is 21013251089. The reversal of 21013251040 is 4015231012.

It is a super-2 number, since 2×21013251040² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21013250999 and 21013251017.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1177867 + ... + 1195573.

It is an arithmetic number, because the mean of its divisors is an integer number (1034443809).

Almost surely, 2^21013251040 is an apocalyptic number.

21013251040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21013251040 is an abundant number, since it is smaller than the sum of its proper divisors (28640051792).

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

21013251040 is a wasteful number, since it uses less digits than its factorization.

21013251040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25139 (or 25131 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 19.

Adding to 21013251040 its reverse (4015231012), we get a palindrome (25028482052).

The spelling of 21013251040 in words is "twenty-one billion, thirteen million, two hundred fifty-one thousand, forty".