8400078 has 16 divisors (see below), whose sum is σ = 18666960. Its totient is φ = 2800008.

The previous prime is 8400061. The next prime is 8400079. The reversal of 8400078 is 8700048.

It is a happy number.

It is a super-2 number, since 2×8400078² = 141122620812168, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8400079) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77725 + ... + 77832.

It is an arithmetic number, because the mean of its divisors is an integer number (1166685).

Almost surely, 2^8400078 is an apocalyptic number.

8400078 is an abundant number, since it is smaller than the sum of its proper divisors (10266882).

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

8400078 is a wasteful number, since it uses less digits than its factorization.

8400078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155568 (or 155562 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 8400078 is about 2898.2888054851. The cubic root of 8400078 is about 203.2799005588.

The spelling of 8400078 in words is "eight million, four hundred thousand, seventy-eight".