2991232978 has 4 divisors (see below), whose sum is σ = 4486849470. Its totient is φ = 1495616488.

The previous prime is 2991232973. The next prime is 2991232987. The reversal of 2991232978 is 8792321992.

2991232978 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 2845475649 + 145757329 = 53343^2 + 12073^2 .

It is not an unprimeable number, because it can be changed into a prime (2991232973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 747808243 + ... + 747808246.

Almost surely, 2^2991232978 is an apocalyptic number.

2991232978 is a deficient number, since it is larger than the sum of its proper divisors (1495616492).

2991232978 is a wasteful number, since it uses less digits than its factorization.

2991232978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1495616491.

The product of its digits is 979776, while the sum is 52.

The square root of 2991232978 is about 54692.1655998371. The cubic root of 2991232978 is about 1440.8432846777.

The spelling of 2991232978 in words is "two billion, nine hundred ninety-one million, two hundred thirty-two thousand, nine hundred seventy-eight".