776981 has 4 divisors (see below), whose sum is σ = 778764. Its totient is φ = 775200.

The previous prime is 776977. The next prime is 776983. The reversal of 776981 is 189677.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 152881 + 624100 = 391^2 + 790^2 .

It is a cyclic number.

It is not a de Polignac number, because 776981 - 2² = 776977 is a prime.

It is a super-2 number, since 2×776981² = 1207398948722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (776983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 251 + ... + 1271.

It is an arithmetic number, because the mean of its divisors is an integer number (194691).

2⁷⁷⁶⁹⁸¹ is an apocalyptic number.

It is an amenable number.

776981 is a deficient number, since it is larger than the sum of its proper divisors (1783).

776981 is a wasteful number, since it uses less digits than its factorization.

776981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1782.

The product of its digits is 21168, while the sum is 38.

The square root of 776981 is about 881.4652573982. The cubic root of 776981 is about 91.9327249191.

The spelling of 776981 in words is "seven hundred seventy-six thousand, nine hundred eighty-one".