78420540015 has 40 divisors (see below), whose sum is σ = 140596724400. Its totient is φ = 41818146048.

The previous prime is 78420540013. The next prime is 78420540049. The reversal of 78420540015 is 51004502487.

78420540015 is a `hidden beast` number, since 7 + 84 + 20 + 540 + 0 + 15 = 666.

It is not a de Polignac number, because 78420540015 - 2¹ = 78420540013 is a prime.

It is a super-2 number, since 2×78420540015² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78420540013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 4567527 + ... + 4584663.

It is an arithmetic number, because the mean of its divisors is an integer number (3514918110).

Almost surely, 2^78420540015 is an apocalyptic number.

78420540015 is a deficient number, since it is larger than the sum of its proper divisors (62176184385).

78420540015 is a wasteful number, since it uses less digits than its factorization.

78420540015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28453 (or 28444 counting only the distinct ones).

The product of its (nonzero) digits is 44800, while the sum is 36.

The spelling of 78420540015 in words is "seventy-eight billion, four hundred twenty million, five hundred forty thousand, fifteen".