78771240 has 48 divisors (see below), whose sum is σ = 256007700. Its totient is φ = 21005568.

The previous prime is 78771239. The next prime is 78771241. The reversal of 78771240 is 4217787.

It is an interprime number because it is at equal distance from previous prime (78771239) and next prime (78771241).

It can be written as a sum of positive squares in 2 ways, for example, as 78535044 + 236196 = 8862^2 + 486^2 .

It is a super-2 number, since 2×78771240² = 12409816502275200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 78771195 and 78771204.

It is not an unprimeable number, because it can be changed into a prime (78771241) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 109045 + ... + 109764.

Almost surely, 2^78771240 is an apocalyptic number.

It is an amenable number.

78771240 is an abundant number, since it is smaller than the sum of its proper divisors (177236460).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78771240 is a wasteful number, since it uses less digits than its factorization.

78771240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218826 (or 218819 counting only the distinct ones).

The product of its (nonzero) digits is 21952, while the sum is 36.

The square root of 78771240 is about 8875.3163323906. The cubic root of 78771240 is about 428.6694766146.

It can be divided in two parts, 787 and 71240, that added together give a palindrome (72027).

The spelling of 78771240 in words is "seventy-eight million, seven hundred seventy-one thousand, two hundred forty".