83777981 has 8 divisors (see below), whose sum is σ = 95801664. Its totient is φ = 71768160.

The previous prime is 83777977. The next prime is 83777987. The reversal of 83777981 is 18977738.

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

It is a cyclic number.

It is not a de Polignac number, because 83777981 - 2² = 83777977 is a prime.

It is a super-2 number, since 2×83777981² = 14037500200872722, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (83777987) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21521 + ... + 25113.

It is an arithmetic number, because the mean of its divisors is an integer number (11975208).

Almost surely, 2^83777981 is an apocalyptic number.

It is an amenable number.

83777981 is a deficient number, since it is larger than the sum of its proper divisors (12023683).

83777981 is a wasteful number, since it uses less digits than its factorization.

83777981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6931.

The product of its digits is 592704, while the sum is 50.

The square root of 83777981 is about 9153.0312465325. The cubic root of 83777981 is about 437.5657257446.

The spelling of 83777981 in words is "eighty-three million, seven hundred seventy-seven thousand, nine hundred eighty-one".