78420040 has 32 divisors (see below), whose sum is σ = 176904000. Its totient is φ = 31286464.

The previous prime is 78420037. The next prime is 78420053. The reversal of 78420040 is 4002487.

It is a super-2 number, since 2×78420040² = 12299405347203200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78419987 and 78420014.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14421 + ... + 19099.

It is an arithmetic number, because the mean of its divisors is an integer number (5528250).

Almost surely, 2^78420040 is an apocalyptic number.

It is an amenable number.

78420040 is an abundant number, since it is smaller than the sum of its proper divisors (98483960).

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

78420040 is a wasteful number, since it uses less digits than its factorization.

78420040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5109 (or 5105 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 25.

The square root of 78420040 is about 8855.5090198136. The cubic root of 78420040 is about 428.0314560396.

The spelling of 78420040 in words is "seventy-eight million, four hundred twenty thousand, forty".