51161993 has 8 divisors (see below), whose sum is σ = 54652968. Its totient is φ = 47724544.

The previous prime is 51161989. The next prime is 51162011. The reversal of 51161993 is 39916115.

It can be written as a sum of positive squares in 4 ways, for example, as 14341369 + 36820624 = 3787^2 + 6068^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 51161993 - 2² = 51161989 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51161923) 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, 11396 + ... + 15237.

It is an arithmetic number, because the mean of its divisors is an integer number (6831621).

Almost surely, 2^51161993 is an apocalyptic number.

It is an amenable number.

51161993 is a deficient number, since it is larger than the sum of its proper divisors (3490975).

51161993 is a wasteful number, since it uses less digits than its factorization.

51161993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26763.

The product of its digits is 7290, while the sum is 35.

The square root of 51161993 is about 7152.7612150833. The cubic root of 51161993 is about 371.2352022428.

The spelling of 51161993 in words is "fifty-one million, one hundred sixty-one thousand, nine hundred ninety-three".