50999981 has 4 divisors (see below), whose sum is σ = 51525852. Its totient is φ = 50474112.

The previous prime is 50999959. The next prime is 50999989. The reversal of 50999981 is 18999905.

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

It can be written as a sum of positive squares in 2 ways, for example, as 38812900 + 12187081 = 6230^2 + 3491^2 .

It is a cyclic number.

It is not a de Polignac number, because 50999981 - 2²² = 46805677 is a prime.

It is a super-2 number, since 2×50999981² = 5201996124000722, 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 (50999989) 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, 262790 + ... + 262983.

It is an arithmetic number, because the mean of its divisors is an integer number (12881463).

Almost surely, 2^50999981 is an apocalyptic number.

It is an amenable number.

50999981 is a deficient number, since it is larger than the sum of its proper divisors (525871).

50999981 is an equidigital number, since it uses as much as digits as its factorization.

50999981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525870.

The product of its (nonzero) digits is 262440, while the sum is 50.

The square root of 50999981 is about 7141.4270982766. The cubic root of 50999981 is about 370.8429308742.

The spelling of 50999981 in words is "fifty million, nine hundred ninety-nine thousand, nine hundred eighty-one".