77481261 has 54 divisors (see below), whose sum is σ = 133523754. Its totient is φ = 43243200.

The previous prime is 77481211. The next prime is 77481269. The reversal of 77481261 is 16218477.

It can be written as a sum of positive squares in 3 ways, for example, as 9418761 + 68062500 = 3069^2 + 8250^2 .

It is not a de Polignac number, because 77481261 - 2¹³ = 77473069 is a prime.

Its product of digits (18816) is a multiple of the sum of its prime divisors (448).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77481269) 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 53 ways as a sum of consecutive naturals, for example, 183831 + ... + 184251.

Almost surely, 2^77481261 is an apocalyptic number.

It is an amenable number.

77481261 is a deficient number, since it is larger than the sum of its proper divisors (56042493).

77481261 is a wasteful number, since it uses less digits than its factorization.

77481261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 475 (or 448 counting only the distinct ones).

The product of its digits is 18816, while the sum is 36.

The square root of 77481261 is about 8802.3440628051. The cubic root of 77481261 is about 426.3165834245.

It can be divided in two parts, 7748 and 1261, that added together give a palindrome (9009).

The spelling of 77481261 in words is "seventy-seven million, four hundred eighty-one thousand, two hundred sixty-one".