9621815540 has 12 divisors (see below), whose sum is σ = 20205812676. Its totient is φ = 3848726208.

The previous prime is 9621815537. The next prime is 9621815549. The reversal of 9621815540 is 455181269.

It can be written as a sum of positive squares in 2 ways, for example, as 6744351376 + 2877464164 = 82124^2 + 53642^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9621815549) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 240545369 + ... + 240545408.

It is an arithmetic number, because the mean of its divisors is an integer number (1683817723).

Almost surely, 2^9621815540 is an apocalyptic number.

It is an amenable number.

9621815540 is an abundant number, since it is smaller than the sum of its proper divisors (10583997136).

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

9621815540 is a wasteful number, since it uses less digits than its factorization.

9621815540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481090786 (or 481090784 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 41.

The square root of 9621815540 is about 98090.8534981728. The cubic root of 9621815540 is about 2126.9258142199.

The spelling of 9621815540 in words is "nine billion, six hundred twenty-one million, eight hundred fifteen thousand, five hundred forty".