78238840 has 32 divisors (see below), whose sum is σ = 176940000. Its totient is φ = 31135104.

The previous prime is 78238819. The next prime is 78238843. The reversal of 78238840 is 4883287.

It is a super-2 number, since 2×78238840² = 12242632169091200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 78238793 and 78238802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78238843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3046 + ... + 12874.

It is an arithmetic number, because the mean of its divisors is an integer number (5529375).

Almost surely, 2^78238840 is an apocalyptic number.

It is an amenable number.

78238840 is an abundant number, since it is smaller than the sum of its proper divisors (98701160).

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

78238840 is a wasteful number, since it uses less digits than its factorization.

78238840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10039 (or 10035 counting only the distinct ones).

The product of its (nonzero) digits is 86016, while the sum is 40.

The square root of 78238840 is about 8845.2721834888. The cubic root of 78238840 is about 427.7015271350.

The spelling of 78238840 in words is "seventy-eight million, two hundred thirty-eight thousand, eight hundred forty".