78402720 has 192 divisors, whose sum is σ = 278691840. Its totient is φ = 18355200.

The previous prime is 78402697. The next prime is 78402743. The reversal of 78402720 is 2720487.

It is an interprime number because it is at equal distance from previous prime (78402697) and next prime (78402743).

It is a super-2 number, since 2×78402720² = 12293973006796800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 163441 + ... + 163919.

It is an arithmetic number, because the mean of its divisors is an integer number (1451520).

Almost surely, 2^78402720 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78402720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139345920).

78402720 is an abundant number, since it is smaller than the sum of its proper divisors (200289120).

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

78402720 is a wasteful number, since it uses less digits than its factorization.

78402720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 539 (or 531 counting only the distinct ones).

The product of its (nonzero) digits is 6272, while the sum is 30.

The square root of 78402720 is about 8854.5310434828. The cubic root of 78402720 is about 427.9999417707. Note that the first 4 decimals are identical.

The spelling of 78402720 in words is "seventy-eight million, four hundred two thousand, seven hundred twenty".