72400431 has 8 divisors (see below), whose sum is σ = 101614720. Its totient is φ = 45726552.

The previous prime is 72400429. The next prime is 72400439. The reversal of 72400431 is 13400427.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 72400431 - 2¹ = 72400429 is a prime.

It is a super-2 number, since 2×72400431² = 10483644817971522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 72400398 and 72400407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72400439) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 635035 + ... + 635148.

It is an arithmetic number, because the mean of its divisors is an integer number (12701840).

Almost surely, 2^72400431 is an apocalyptic number.

72400431 is a deficient number, since it is larger than the sum of its proper divisors (29214289).

72400431 is a wasteful number, since it uses less digits than its factorization.

72400431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1270205.

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 72400431 is about 8508.8442810995. The cubic root of 72400431 is about 416.7865707897.

Adding to 72400431 its reverse (13400427), we get a palindrome (85800858).

The spelling of 72400431 in words is "seventy-two million, four hundred thousand, four hundred thirty-one".