78042901 has 4 divisors (see below), whose sum is σ = 78169600. Its totient is φ = 77916204.

The previous prime is 78042863. The next prime is 78042907. The reversal of 78042901 is 10924087.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 10924087 = 1889 ⋅5783.

It is a cyclic number.

It is not a de Polignac number, because 78042901 - 2¹⁵ = 78010133 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78042907) 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, 62421 + ... + 63658.

It is an arithmetic number, because the mean of its divisors is an integer number (19542400).

Almost surely, 2^78042901 is an apocalyptic number.

It is an amenable number.

78042901 is a deficient number, since it is larger than the sum of its proper divisors (126699).

78042901 is a wasteful number, since it uses less digits than its factorization.

78042901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126698.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 78042901 is about 8834.1893233052. The cubic root of 78042901 is about 427.3441877144.

Adding to 78042901 its reverse (10924087), we get a palindrome (88966988).

It can be divided in two parts, 780 and 42901, that added together give a square (43681 = 209²).

The spelling of 78042901 in words is "seventy-eight million, forty-two thousand, nine hundred one".