9131557121640 has 512 divisors, whose sum is σ = 35400333312000. Its totient is φ = 2076815904768.

The previous prime is 9131557121629. The next prime is 9131557121669. The reversal of 9131557121640 is 461217551319.

9131557121640 is a `hidden beast` number, since 9 + 1 + 3 + 15 + 571 + 2 + 1 + 64 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 7454257 + ... + 8592383.

It is an arithmetic number, because the mean of its divisors is an integer number (69141276000).

Almost surely, 2^{9131557121640} is an apocalyptic number.

9131557121640 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9131557121640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17700166656000).

9131557121640 is an abundant number, since it is smaller than the sum of its proper divisors (26268776190360).

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

9131557121640 is a wasteful number, since it uses less digits than its factorization.

9131557121640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1138206 (or 1138196 counting only the distinct ones).

The product of its (nonzero) digits is 226800, while the sum is 45.

The spelling of 9131557121640 in words is "nine trillion, one hundred thirty-one billion, five hundred fifty-seven million, one hundred twenty-one thousand, six hundred forty".