61320431 has 4 divisors (see below), whose sum is σ = 61491600. Its totient is φ = 61149264.

The previous prime is 61320421. The next prime is 61320443. The reversal of 61320431 is 13402316.

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 61320431 - 2⁶ = 61320367 is a prime.

It is a super-2 number, since 2×61320431² = 7520390516051522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61320401) 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, 85046 + ... + 85763.

It is an arithmetic number, because the mean of its divisors is an integer number (15372900).

Almost surely, 2^61320431 is an apocalyptic number.

61320431 is a deficient number, since it is larger than the sum of its proper divisors (171169).

61320431 is a wasteful number, since it uses less digits than its factorization.

61320431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171168.

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 61320431 is about 7830.7362999912. The cubic root of 61320431 is about 394.3377912593.

Adding to 61320431 its reverse (13402316), we get a palindrome (74722747).

The spelling of 61320431 in words is "sixty-one million, three hundred twenty thousand, four hundred thirty-one".