2551791842 has 4 divisors (see below), whose sum is σ = 3827687766. Its totient is φ = 1275895920.

The previous prime is 2551791841. The next prime is 2551791863. The reversal of 2551791842 is 2481971552.

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., 2350407361 + 201384481 = 48481^2 + 14191^2 .

It is a junction number, because it is equal to n+sod(n) for n = 2551791793 and 2551791802.

It is not an unprimeable number, because it can be changed into a prime (2551791841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 637947959 + ... + 637947962.

Almost surely, 2^2551791842 is an apocalyptic number.

2551791842 is a deficient number, since it is larger than the sum of its proper divisors (1275895924).

2551791842 is a wasteful number, since it uses less digits than its factorization.

2551791842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1275895923.

The product of its digits is 201600, while the sum is 44.

The square root of 2551791842 is about 50515.2634557121. The cubic root of 2551791842 is about 1366.5171343701.

The spelling of 2551791842 in words is "two billion, five hundred fifty-one million, seven hundred ninety-one thousand, eight hundred forty-two".