78154807645553 has 16 divisors (see below), whose sum is σ = 83677777318800. Its totient is φ = 72736000966656.

The previous prime is 78154807645507. The next prime is 78154807645571. The reversal of 78154807645553 is 35554670845187.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 977739283249 + 77177068362304 = 988807^2 + 8785048^2 .

It is a cyclic number.

It is not a de Polignac number, because 78154807645553 - 2¹² = 78154807641457 is a prime.

It is a super-2 number, since 2×78154807645553² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78154807945553) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18651728 + ... + 22454321.

It is an arithmetic number, because the mean of its divisors is an integer number (5229861082425).

Almost surely, 2^{78154807645553} is an apocalyptic number.

It is an amenable number.

78154807645553 is a deficient number, since it is larger than the sum of its proper divisors (5522969673247).

78154807645553 is a wasteful number, since it uses less digits than its factorization.

78154807645553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41107316.

The product of its (nonzero) digits is 564480000, while the sum is 68.

The spelling of 78154807645553 in words is "seventy-eight trillion, one hundred fifty-four billion, eight hundred seven million, six hundred forty-five thousand, five hundred fifty-three".