78406555 has 16 divisors (see below), whose sum is σ = 97401024. Its totient is φ = 60549120.

The previous prime is 78406553. The next prime is 78406583. The reversal of 78406555 is 55560487.

It is not a de Polignac number, because 78406555 - 2¹ = 78406553 is a prime.

It is a super-2 number, since 2×78406555² = 12295175733936050, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78406553) 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, 17914 + ... + 21856.

It is an arithmetic number, because the mean of its divisors is an integer number (6087564).

Almost surely, 2^78406555 is an apocalyptic number.

78406555 is a deficient number, since it is larger than the sum of its proper divisors (18994469).

78406555 is a wasteful number, since it uses less digits than its factorization.

78406555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4086.

The product of its (nonzero) digits is 168000, while the sum is 40.

The square root of 78406555 is about 8854.7475966286. The cubic root of 78406555 is about 428.0069200704.

It can be divided in two parts, 78406 and 555, that added together give a square (78961 = 281²).

The spelling of 78406555 in words is "seventy-eight million, four hundred six thousand, five hundred fifty-five".