77520981 has 8 divisors (see below), whose sum is σ = 103539744. Its totient is φ = 51591440.

The previous prime is 77520977. The next prime is 77520983. The reversal of 77520981 is 18902577.

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 77520981 - 2² = 77520977 is a prime.

It is a super-2 number, since 2×77520981² = 12019004990404722, 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 (77520983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20250 + ... + 23771.

It is an arithmetic number, because the mean of its divisors is an integer number (12942468).

Almost surely, 2^77520981 is an apocalyptic number.

It is an amenable number.

77520981 is a deficient number, since it is larger than the sum of its proper divisors (26018763).

77520981 is a wasteful number, since it uses less digits than its factorization.

77520981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44611.

The product of its (nonzero) digits is 35280, while the sum is 39.

The square root of 77520981 is about 8804.5999909138. The cubic root of 77520981 is about 426.3894199691.

The spelling of 77520981 in words is "seventy-seven million, five hundred twenty thousand, nine hundred eighty-one".