78238100 has 18 divisors (see below), whose sum is σ = 169776894. Its totient is φ = 31295200.

The previous prime is 78238099. The next prime is 78238103. The reversal of 78238100 is 183287.

It can be written as a sum of positive squares in 3 ways, for example, as 586756 + 77651344 = 766^2 + 8812^2 .

It is a super-2 number, since 2×78238100² = 12242400583220000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78238103) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 391091 + ... + 391290.

Almost surely, 2^78238100 is an apocalyptic number.

It is an amenable number.

78238100 is an abundant number, since it is smaller than the sum of its proper divisors (91538794).

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

78238100 is a wasteful number, since it uses less digits than its factorization.

78238100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782395 (or 782388 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 78238100 is about 8845.2303531338. The cubic root of 78238100 is about 427.7001786993.

The spelling of 78238100 in words is "seventy-eight million, two hundred thirty-eight thousand, one hundred".