2781939897 has 40 divisors (see below), whose sum is σ = 4601295072. Its totient is φ = 1660824000.

The previous prime is 2781939887. The next prime is 2781939899. The reversal of 2781939897 is 7989391872.

2781939897 is a `hidden beast` number, since 278 + 193 + 98 + 97 = 666.

It is not a de Polignac number, because 2781939897 - 2⁶ = 2781939833 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2781939899) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 36397 + ... + 82997.

Almost surely, 2^2781939897 is an apocalyptic number.

2781939897 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

2781939897 is a deficient number, since it is larger than the sum of its proper divisors (1819355175).

2781939897 is a wasteful number, since it uses less digits than its factorization.

2781939897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46691 (or 46682 counting only the distinct ones).

The product of its digits is 13716864, while the sum is 63.

The square root of 2781939897 is about 52744.0982196113. The cubic root of 2781939897 is about 1406.4228519260.

The spelling of 2781939897 in words is "two billion, seven hundred eighty-one million, nine hundred thirty-nine thousand, eight hundred ninety-seven".