78049477538 has 4 divisors (see below), whose sum is σ = 117074216310. Its totient is φ = 39024738768.

The previous prime is 78049477487. The next prime is 78049477567. The reversal of 78049477538 is 83577494087.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83577494087 = 223 ⋅374786969.

It can be written as a sum of positive squares in only one way, i.e., 77463692329 + 585785209 = 278323^2 + 24203^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19512369383 + ... + 19512369386.

Almost surely, 2^78049477538 is an apocalyptic number.

78049477538 is a deficient number, since it is larger than the sum of its proper divisors (39024738772).

78049477538 is a wasteful number, since it uses less digits than its factorization.

78049477538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39024738771.

The product of its (nonzero) digits is 47416320, while the sum is 62.

The spelling of 78049477538 in words is "seventy-eight billion, forty-nine million, four hundred seventy-seven thousand, five hundred thirty-eight".