77445121320 has 288 divisors, whose sum is σ = 302236945920. Its totient is φ = 17130597120.

The previous prime is 77445121309. The next prime is 77445121331. The reversal of 77445121320 is 2312154477.

77445121320 is a `hidden beast` number, since 7 + 7 + 4 + 4 + 512 + 132 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (77445121309) and next prime (77445121331).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 476029 + ... + 617651.

It is an arithmetic number, because the mean of its divisors is an integer number (1049433840).

Almost surely, 2^77445121320 is an apocalyptic number.

77445121320 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77445121320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (151118472960).

77445121320 is an abundant number, since it is smaller than the sum of its proper divisors (224791824600).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77445121320 is a wasteful number, since it uses less digits than its factorization.

77445121320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141685 (or 141671 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 36.

Adding to 77445121320 its reverse (2312154477), we get a palindrome (79757275797).

It can be divided in two parts, 77445 and 121320, that added together give a triangular number (198765 = T₆₃₀).

The spelling of 77445121320 in words is "seventy-seven billion, four hundred forty-five million, one hundred twenty-one thousand, three hundred twenty".