78401628 has 48 divisors (see below), whose sum is σ = 207113760. Its totient is φ = 25638912.

The previous prime is 78401627. The next prime is 78401693. The reversal of 78401628 is 82610487.

It is a super-2 number, since 2×78401628² = 12293630546100768, 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 = 78401592 and 78401601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78401627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1125 + ... + 12572.

It is an arithmetic number, because the mean of its divisors is an integer number (4314870).

Almost surely, 2^78401628 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 78401628, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103556880).

78401628 is an abundant number, since it is smaller than the sum of its proper divisors (128712132).

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

78401628 is a wasteful number, since it uses less digits than its factorization.

78401628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13763 (or 13755 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 78401628 is about 8854.4693799233. The cubic root of 78401628 is about 427.9979546879.

The spelling of 78401628 in words is "seventy-eight million, four hundred one thousand, six hundred twenty-eight".