78420736 has 18 divisors (see below), whose sum is σ = 156535652. Its totient is φ = 39210240.

The previous prime is 78420721. The next prime is 78420737. The reversal of 78420736 is 63702487.

It is a super-2 number, since 2×78420736² = 12299623669563392, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78420695 and 78420704.

It is not an unprimeable number, because it can be changed into a prime (78420737) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 152910 + ... + 153421.

Almost surely, 2^78420736 is an apocalyptic number.

It is an amenable number.

78420736 is a deficient number, since it is larger than the sum of its proper divisors (78114916).

78420736 is an equidigital number, since it uses as much as digits as its factorization.

78420736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306347 (or 306333 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 37.

The square root of 78420736 is about 8855.5483172980. The cubic root of 78420736 is about 428.0327223359.

It can be divided in two parts, 784 and 20736, that multiplied together give a square (16257024 = 4032²).

The spelling of 78420736 in words is "seventy-eight million, four hundred twenty thousand, seven hundred thirty-six".