2991122478 has 48 divisors (see below), whose sum is σ = 6734263536. Its totient is φ = 995042880.

The previous prime is 2991122467. The next prime is 2991122479. The reversal of 2991122478 is 8742211992.

2991122478 is a `hidden beast` number, since 299 + 112 + 247 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2991122479) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 247300 + ... + 259112.

It is an arithmetic number, because the mean of its divisors is an integer number (140297157).

Almost surely, 2^2991122478 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2991122478, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3367131768).

2991122478 is an abundant number, since it is smaller than the sum of its proper divisors (3743141058).

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

2991122478 is a wasteful number, since it uses less digits than its factorization.

2991122478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12351 (or 12339 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 2991122478 is about 54691.1553909771. The cubic root of 2991122478 is about 1440.8255422568.

The spelling of 2991122478 in words is "two billion, nine hundred ninety-one million, one hundred twenty-two thousand, four hundred seventy-eight".