49971991 has 2 divisors, whose sum is σ = 49971992. Its totient is φ = 49971990.

The previous prime is 49971979. The next prime is 49972009. The reversal of 49971991 is 19917994.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 49971991 - 2¹⁹ = 49447703 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (49971091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 24985995 + 24985996.

It is an arithmetic number, because the mean of its divisors is an integer number (24985996).

Almost surely, 2^49971991 is an apocalyptic number.

49971991 is a deficient number, since it is larger than the sum of its proper divisors (1).

49971991 is an equidigital number, since it uses as much as digits as its factorization.

49971991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 183708, while the sum is 49.

The square root of 49971991 is about 7069.0869990403. The cubic root of 49971991 is about 368.3343463228.

The spelling of 49971991 in words is "forty-nine million, nine hundred seventy-one thousand, nine hundred ninety-one".