78390621355 has 32 divisors (see below), whose sum is σ = 98716475520. Its totient is φ = 59645752320.

The previous prime is 78390621343. The next prime is 78390621371. The reversal of 78390621355 is 55312609387.

It is not a de Polignac number, because 78390621355 - 2⁹ = 78390620843 is a prime.

It is a super-2 number, since 2×78390621355² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78390621299 and 78390621308.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 25212541 + ... + 25215649.

It is an arithmetic number, because the mean of its divisors is an integer number (3084889860).

Almost surely, 2^78390621355 is an apocalyptic number.

78390621355 is a deficient number, since it is larger than the sum of its proper divisors (20325854165).

78390621355 is a wasteful number, since it uses less digits than its factorization.

78390621355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4311.

The product of its (nonzero) digits is 1360800, while the sum is 49.

The spelling of 78390621355 in words is "seventy-eight billion, three hundred ninety million, six hundred twenty-one thousand, three hundred fifty-five".