21400840307650 has 12 divisors (see below), whose sum is σ = 39805562972322. Its totient is φ = 8560336123040.

The previous prime is 21400840307621. The next prime is 21400840307657. The reversal of 21400840307650 is 5670304800412.

It can be written as a sum of positive squares in 3 ways, for example, as 15631087382689 + 5769752924961 = 3953617^2 + 2402031^2 .

It is not an unprimeable number, because it can be changed into a prime (21400840307657) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 214008403027 + ... + 214008403126.

Almost surely, 2^{21400840307650} is an apocalyptic number.

21400840307650 is a deficient number, since it is larger than the sum of its proper divisors (18404722664672).

21400840307650 is a wasteful number, since it uses less digits than its factorization.

21400840307650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428016806165 (or 428016806160 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 40.

The spelling of 21400840307650 in words is "twenty-one trillion, four hundred billion, eight hundred forty million, three hundred seven thousand, six hundred fifty".