78253634 has 4 divisors (see below), whose sum is σ = 117380454. Its totient is φ = 39126816.

The previous prime is 78253633. The next prime is 78253663. The reversal of 78253634 is 43635287.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 43635287 = 191 ⋅228457.

It can be written as a sum of positive squares in only one way, i.e., 45225625 + 33028009 = 6725^2 + 5747^2 .

It is a super-2 number, since 2×78253634² = 12247262468411912, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78253633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19563407 + ... + 19563410.

Almost surely, 2^78253634 is an apocalyptic number.

78253634 is a deficient number, since it is larger than the sum of its proper divisors (39126820).

78253634 is a wasteful number, since it uses less digits than its factorization.

78253634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39126819.

The product of its digits is 120960, while the sum is 38.

The square root of 78253634 is about 8846.1084099168. The cubic root of 78253634 is about 427.7284831312.

It can be divided in two parts, 78253 and 634, that added together give a palindrome (78887).

The spelling of 78253634 in words is "seventy-eight million, two hundred fifty-three thousand, six hundred thirty-four".