77926981 has 4 divisors (see below), whose sum is σ = 85011264. Its totient is φ = 70842700.

The previous prime is 77926949. The next prime is 77926993. The reversal of 77926981 is 18962977.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 77926981 - 2⁵ = 77926949 is a prime.

It is a super-2 number, since 2×77926981² = 12145228735548722, 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 (77926931) 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, 3542125 + ... + 3542146.

It is an arithmetic number, because the mean of its divisors is an integer number (21252816).

Almost surely, 2^77926981 is an apocalyptic number.

It is an amenable number.

77926981 is a deficient number, since it is larger than the sum of its proper divisors (7084283).

77926981 is a wasteful number, since it uses less digits than its factorization.

77926981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7084282.

The product of its digits is 381024, while the sum is 49.

The square root of 77926981 is about 8827.6260115617. The cubic root of 77926981 is about 427.1324995078.

The spelling of 77926981 in words is "seventy-seven million, nine hundred twenty-six thousand, nine hundred eighty-one".