78249420 has 36 divisors (see below), whose sum is σ = 237357120. Its totient is φ = 20866464.

The previous prime is 78249401. The next prime is 78249433. The reversal of 78249420 is 2494287.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×78249420² = 12245943460672800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 217180 + ... + 217539.

Almost surely, 2^78249420 is an apocalyptic number.

It is an amenable number.

78249420 is an abundant number, since it is smaller than the sum of its proper divisors (159107700).

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

78249420 is a wasteful number, since it uses less digits than its factorization.

78249420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 434734 (or 434729 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 78249420 is about 8845.8702228780. The cubic root of 78249420 is about 427.7208051909.

The spelling of 78249420 in words is "seventy-eight million, two hundred forty-nine thousand, four hundred twenty".