77066557 has 4 divisors (see below), whose sum is σ = 77814880. Its totient is φ = 76318236.

The previous prime is 77066551. The next prime is 77066569. The reversal of 77066557 is 75566077.

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, and also an emirpimes, since its reverse is a distinct semiprime: 75566077 = 2803 ⋅26959.

It is a cyclic number.

It is not a de Polignac number, because 77066557 - 2¹⁹ = 76542269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77066551) 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, 374007 + ... + 374212.

It is an arithmetic number, because the mean of its divisors is an integer number (19453720).

Almost surely, 2^77066557 is an apocalyptic number.

It is an amenable number.

77066557 is a deficient number, since it is larger than the sum of its proper divisors (748323).

77066557 is a wasteful number, since it uses less digits than its factorization.

77066557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 748322.

The product of its (nonzero) digits is 308700, while the sum is 43.

The square root of 77066557 is about 8778.7560052663. The cubic root of 77066557 is about 425.5546290608.

The spelling of 77066557 in words is "seventy-seven million, sixty-six thousand, five hundred fifty-seven".