21400530724 has 24 divisors (see below), whose sum is σ = 38458287000. Its totient is φ = 10413726720.

The previous prime is 21400530709. The next prime is 21400530761. The reversal of 21400530724 is 42703500412.

It can be written as a sum of positive squares in 4 ways, for example, as 2167833600 + 19232697124 = 46560^2 + 138682^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21400530692 and 21400530701.

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, 92449 + ... + 226600.

It is an arithmetic number, because the mean of its divisors is an integer number (1602428625).

Almost surely, 2^21400530724 is an apocalyptic number.

It is an amenable number.

21400530724 is a deficient number, since it is larger than the sum of its proper divisors (17057756276).

21400530724 is a wasteful number, since it uses less digits than its factorization.

21400530724 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 319503 (or 319501 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 28.

The spelling of 21400530724 in words is "twenty-one billion, four hundred million, five hundred thirty thousand, seven hundred twenty-four".