78400487 has 16 divisors (see below), whose sum is σ = 88349184. Its totient is φ = 68952000.

The previous prime is 78400477. The next prime is 78400489.

78400487 is nontrivially palindromic in base 10.

It is a cyclic number.

It is not a de Polignac number, because 78400487 - 2⁴ = 78400471 is a prime.

It is a super-2 number, since 2×78400487² = 12293272723674338, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78400487.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78400489) 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, 58418 + ... + 59744.

It is an arithmetic number, because the mean of its divisors is an integer number (5521824).

Almost surely, 2^78400487 is an apocalyptic number.

78400487 is a deficient number, since it is larger than the sum of its proper divisors (9948697).

78400487 is a wasteful number, since it uses less digits than its factorization.

78400487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1510.

The product of its (nonzero) digits is 50176, while the sum is 38.

The square root of 78400487 is about 8854.4049489506. The cubic root of 78400487 is about 427.9958784213.

It can be divided in two parts, 78400 and 487, that added together give a palindrome (78887).

The spelling of 78400487 in words is "seventy-eight million, four hundred thousand, four hundred eighty-seven".