77481551 has 4 divisors (see below), whose sum is σ = 88550352. Its totient is φ = 66412752.

The previous prime is 77481539. The next prime is 77481553. The reversal of 77481551 is 15518477.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15518477 = 13 ⋅1193729.

It is not a de Polignac number, because 77481551 - 2¹⁰ = 77480527 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 (77481553) 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, 5534390 + ... + 5534403.

It is an arithmetic number, because the mean of its divisors is an integer number (22137588).

Almost surely, 2^77481551 is an apocalyptic number.

77481551 is a deficient number, since it is larger than the sum of its proper divisors (11068801).

77481551 is a wasteful number, since it uses less digits than its factorization.

77481551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11068800.

The product of its digits is 39200, while the sum is 38.

The square root of 77481551 is about 8802.3605356745. The cubic root of 77481551 is about 426.3171153022.

The spelling of 77481551 in words is "seventy-seven million, four hundred eighty-one thousand, five hundred fifty-one".