51601309 has 4 divisors (see below), whose sum is σ = 52328160. Its totient is φ = 50874460.

The previous prime is 51601289. The next prime is 51601313. The reversal of 51601309 is 90310615.

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: 90310615 = 5 ⋅18062123.

It is a cyclic number.

It is not a de Polignac number, because 51601309 - 2²¹ = 49504157 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 (51601369) 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, 363319 + ... + 363460.

It is an arithmetic number, because the mean of its divisors is an integer number (13082040).

Almost surely, 2^51601309 is an apocalyptic number.

It is an amenable number.

51601309 is a deficient number, since it is larger than the sum of its proper divisors (726851).

51601309 is an equidigital number, since it uses as much as digits as its factorization.

51601309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 726850.

The product of its (nonzero) digits is 810, while the sum is 25.

The square root of 51601309 is about 7183.4051117837. The cubic root of 51601309 is about 372.2947451108.

The spelling of 51601309 in words is "fifty-one million, six hundred one thousand, three hundred nine".