991467540 has 480 divisors, whose sum is σ = 3893218560. Its totient is φ = 206032896.

The previous prime is 991467527. The next prime is 991467553. The reversal of 991467540 is 45764199.

991467540 is a `hidden beast` number, since 99 + 14 + 6 + 7 + 540 = 666.

It is an interprime number because it is at equal distance from previous prime (991467527) and next prime (991467553).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 7132791 + ... + 7132929.

It is an arithmetic number, because the mean of its divisors is an integer number (8110872).

Almost surely, 2^991467540 is an apocalyptic number.

991467540 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 991467540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1946609280).

991467540 is an abundant number, since it is smaller than the sum of its proper divisors (2901751020).

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

991467540 is a wasteful number, since it uses less digits than its factorization.

991467540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221 (or 210 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 45.

The square root of 991467540 is about 31487.5775505198. The cubic root of 991467540 is about 997.1477188941.

The spelling of 991467540 in words is "nine hundred ninety-one million, four hundred sixty-seven thousand, five hundred forty".