991502140 has 72 divisors (see below), whose sum is σ = 2182057920. Its totient is φ = 378368640.

The previous prime is 991502131. The next prime is 991502143. The reversal of 991502140 is 41205199.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991502143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1518054 + ... + 1518706.

It is an arithmetic number, because the mean of its divisors is an integer number (30306360).

Almost surely, 2^991502140 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 991502140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1091028960).

991502140 is an abundant number, since it is smaller than the sum of its proper divisors (1190555780).

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

991502140 is a wasteful number, since it uses less digits than its factorization.

991502140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 803 (or 770 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 31.

The square root of 991502140 is about 31488.1269687481. The cubic root of 991502140 is about 997.1593181677.

The spelling of 991502140 in words is "nine hundred ninety-one million, five hundred two thousand, one hundred forty".