2978631691 has 32 divisors (see below), whose sum is σ = 3622095360. Its totient is φ = 2392747776.

The previous prime is 2978631679. The next prime is 2978631701. The reversal of 2978631691 is 1961368792.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 2978631691 - 2¹⁹ = 2978107403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2978631661) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8583780 + ... + 8584126.

It is an arithmetic number, because the mean of its divisors is an integer number (113190480).

Almost surely, 2^2978631691 is an apocalyptic number.

2978631691 is a deficient number, since it is larger than the sum of its proper divisors (643463669).

2978631691 is a wasteful number, since it uses less digits than its factorization.

2978631691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 883.

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

The square root of 2978631691 is about 54576.8420761040. The cubic root of 2978631691 is about 1438.8171373886.

The spelling of 2978631691 in words is "two billion, nine hundred seventy-eight million, six hundred thirty-one thousand, six hundred ninety-one".