78420502 has 8 divisors (see below), whose sum is σ = 119559312. Its totient is φ = 38567400.

The previous prime is 78420497. The next prime is 78420509. The reversal of 78420502 is 20502487.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×78420502² = 12299550267864008, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78420509) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 321274 + ... + 321517.

It is an arithmetic number, because the mean of its divisors is an integer number (14944914).

Almost surely, 2^78420502 is an apocalyptic number.

78420502 is a deficient number, since it is larger than the sum of its proper divisors (41138810).

78420502 is a wasteful number, since it uses less digits than its factorization.

78420502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 642854.

The product of its (nonzero) digits is 4480, while the sum is 28.

The square root of 78420502 is about 8855.5351052322. The cubic root of 78420502 is about 428.0322965992.

Adding to 78420502 its reverse (20502487), we get a palindrome (98922989).

The spelling of 78420502 in words is "seventy-eight million, four hundred twenty thousand, five hundred two".