78061557 has 36 divisors (see below), whose sum is σ = 127869696. Its totient is φ = 42230160.

The previous prime is 78061553. The next prime is 78061561. The reversal of 78061557 is 75516087.

It is an interprime number because it is at equal distance from previous prime (78061553) and next prime (78061561).

It is not a de Polignac number, because 78061557 - 2² = 78061553 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78061553) by changing a digit.

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 35 ways as a sum of consecutive naturals, for example, 52332 + ... + 53802.

It is an arithmetic number, because the mean of its divisors is an integer number (3551936).

Almost surely, 2^78061557 is an apocalyptic number.

It is an amenable number.

78061557 is a deficient number, since it is larger than the sum of its proper divisors (49808139).

78061557 is a wasteful number, since it uses less digits than its factorization.

78061557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1526 (or 1500 counting only the distinct ones).

The product of its (nonzero) digits is 58800, while the sum is 39.

The square root of 78061557 is about 8835.2451578889. The cubic root of 78061557 is about 427.3782369270.

The spelling of 78061557 in words is "seventy-eight million, sixty-one thousand, five hundred fifty-seven".