981778137 has 8 divisors (see below), whose sum is σ = 1316876736. Its totient is φ = 650599152.

The previous prime is 981778123. The next prime is 981778139. The reversal of 981778137 is 731877189.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 981778137 - 2⁴ = 981778121 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 981778137.

It is not an unprimeable number, because it can be changed into a prime (981778139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 979318 + ... + 980319.

It is an arithmetic number, because the mean of its divisors is an integer number (164609592).

Almost surely, 2^981778137 is an apocalyptic number.

It is an amenable number.

981778137 is a deficient number, since it is larger than the sum of its proper divisors (335098599).

981778137 is a wasteful number, since it uses less digits than its factorization.

981778137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1959807.

The product of its digits is 592704, while the sum is 51.

The square root of 981778137 is about 31333.3390656023. The cubic root of 981778137 is about 993.8887746704. Note that the first 3 decimals are identical.

The spelling of 981778137 in words is "nine hundred eighty-one million, seven hundred seventy-eight thousand, one hundred thirty-seven".