77215481 has 16 divisors (see below), whose sum is σ = 89800704. Its totient is φ = 65028624.

The previous prime is 77215477. The next prime is 77215493. The reversal of 77215481 is 18451277.

It is a cyclic number.

It is not a de Polignac number, because 77215481 - 2² = 77215477 is a prime.

It is a super-2 number, since 2×77215481² = 11924461012122722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (77215441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 201416 + ... + 201798.

It is an arithmetic number, because the mean of its divisors is an integer number (5612544).

Almost surely, 2^77215481 is an apocalyptic number.

It is an amenable number.

77215481 is a deficient number, since it is larger than the sum of its proper divisors (12585223).

77215481 is a wasteful number, since it uses less digits than its factorization.

77215481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 820.

The product of its digits is 15680, while the sum is 35.

The square root of 77215481 is about 8787.2339789037. The cubic root of 77215481 is about 425.8285676818.

The spelling of 77215481 in words is "seventy-seven million, two hundred fifteen thousand, four hundred eighty-one".