78021420 has 48 divisors (see below), whose sum is σ = 225512448. Its totient is φ = 20134080.

The previous prime is 78021409. The next prime is 78021421. The reversal of 78021420 is 2412087.

It is not an unprimeable number, because it can be changed into a prime (78021421) 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, 19114 + ... + 22833.

It is an arithmetic number, because the mean of its divisors is an integer number (4698176).

Almost surely, 2^78021420 is an apocalyptic number.

It is an amenable number.

78021420 is an abundant number, since it is smaller than the sum of its proper divisors (147491028).

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

78021420 is a wasteful number, since it uses less digits than its factorization.

78021420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41990 (or 41988 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 78021420 is about 8832.9734517885. The cubic root of 78021420 is about 427.3049758504.

The spelling of 78021420 in words is "seventy-eight million, twenty-one thousand, four hundred twenty".