78251401 has 4 divisors (see below), whose sum is σ = 79323412. Its totient is φ = 77179392.

The previous prime is 78251399. The next prime is 78251413. The reversal of 78251401 is 10415287.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19713600 + 58537801 = 4440^2 + 7651^2 .

It is a cyclic number.

It is not a de Polignac number, because 78251401 - 2¹ = 78251399 is a prime.

It is a super-2 number, since 2×78251401² = 12246563516925602, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78251401.

It is not an unprimeable number, because it can be changed into a prime (78251441) 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, 535896 + ... + 536041.

It is an arithmetic number, because the mean of its divisors is an integer number (19830853).

Almost surely, 2^78251401 is an apocalyptic number.

It is an amenable number.

78251401 is a deficient number, since it is larger than the sum of its proper divisors (1072011).

78251401 is a wasteful number, since it uses less digits than its factorization.

78251401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1072010.

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 78251401 is about 8845.9821953246. The cubic root of 78251401 is about 427.7244146224.

Adding to 78251401 its reverse (10415287), we get a palindrome (88666688).

The spelling of 78251401 in words is "seventy-eight million, two hundred fifty-one thousand, four hundred one".