49121981 has 2 divisors, whose sum is σ = 49121982. Its totient is φ = 49121980.

The previous prime is 49121971. The next prime is 49121999. The reversal of 49121981 is 18912194.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48372025 + 749956 = 6955^2 + 866^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-49121981 is a prime.

It is a super-3 number, since 3×49121981³ (a number of 24 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (49121971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 24560990 + 24560991.

It is an arithmetic number, because the mean of its divisors is an integer number (24560991).

Almost surely, 2^49121981 is an apocalyptic number.

It is an amenable number.

49121981 is a deficient number, since it is larger than the sum of its proper divisors (1).

49121981 is an equidigital number, since it uses as much as digits as its factorization.

49121981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 35.

The square root of 49121981 is about 7008.7075128015. The cubic root of 49121981 is about 366.2339695640.

The spelling of 49121981 in words is "forty-nine million, one hundred twenty-one thousand, nine hundred eighty-one".