77355740641 has 9 divisors (see below), whose sum is σ = 79513519449. Its totient is φ = 75255032304.

The previous prime is 77355740617. The next prime is 77355740677. The reversal of 77355740641 is 14604755377.

The square root of 77355740641 is 278129.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 53787350241 + 23568390400 = 231921^2 + 153520^2 .

It is not a de Polignac number, because 77355740641 - 2¹³ = 77355732449 is a prime.

It is a super-2 number, since 2×77355740641² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77355720641) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 10287015 + ... + 10294531.

Almost surely, 2^77355740641 is an apocalyptic number.

77355740641 is the 278129-th square number.

77355740641 is the 139065-th centered octagonal number.

It is an amenable number.

77355740641 is a deficient number, since it is larger than the sum of its proper divisors (2157778808).

77355740641 is an frugal number, since it uses more digits than its factorization.

77355740641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15108 (or 7554 counting only the distinct ones).

The product of its (nonzero) digits is 2469600, while the sum is 49.

Multiplying 77355740641 by its sum of digits (49), we get a square (3790431291409 = 1946903²).

The spelling of 77355740641 in words is "seventy-seven billion, three hundred fifty-five million, seven hundred forty thousand, six hundred forty-one".