72400427 has 4 divisors (see below), whose sum is σ = 78982296. Its totient is φ = 65818560.

The previous prime is 72400417. The next prime is 72400429.

72400427 is nontrivially palindromic in base 10.

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

It is a cyclic number.

It is not a de Polignac number, because 72400427 - 2¹⁶ = 72334891 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 72400396 and 72400405.

It is not an unprimeable number, because it can be changed into a prime (72400429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3290918 + ... + 3290939.

It is an arithmetic number, because the mean of its divisors is an integer number (19745574).

Almost surely, 2^72400427 is an apocalyptic number.

72400427 is a deficient number, since it is larger than the sum of its proper divisors (6581869).

72400427 is a wasteful number, since it uses less digits than its factorization.

72400427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6581868.

The product of its (nonzero) digits is 3136, while the sum is 26.

The square root of 72400427 is about 8508.8440460500. The cubic root of 72400427 is about 416.7865631141.

It can be divided in two parts, 72400 and 427, that added together give a palindrome (72827).

The spelling of 72400427 in words is "seventy-two million, four hundred thousand, four hundred twenty-seven".