991415040 has 432 divisors, whose sum is σ = 4026516480. Its totient is φ = 205578240.

The previous prime is 991415021. The next prime is 991415081. The reversal of 991415040 is 40514199.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 991414992 and 991415010.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2069521 + ... + 2069999.

It is an arithmetic number, because the mean of its divisors is an integer number (9320640).

Almost surely, 2^991415040 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991415040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2013258240).

991415040 is an abundant number, since it is smaller than the sum of its proper divisors (3035101440).

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

991415040 is a wasteful number, since it uses less digits than its factorization.

991415040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528 (or 507 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 991415040 is about 31486.7438773843. The cubic root of 991415040 is about 997.1301183248.

The spelling of 991415040 in words is "nine hundred ninety-one million, four hundred fifteen thousand, forty".