49999821 has 4 divisors (see below), whose sum is σ = 66666432. Its totient is φ = 33333212.

The previous prime is 49999819. The next prime is 49999843. The reversal of 49999821 is 12899994.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 49999821 - 2¹ = 49999819 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (49999801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8333301 + ... + 8333306.

It is an arithmetic number, because the mean of its divisors is an integer number (16666608).

Almost surely, 2^49999821 is an apocalyptic number.

It is an amenable number.

49999821 is a deficient number, since it is larger than the sum of its proper divisors (16666611).

49999821 is a wasteful number, since it uses less digits than its factorization.

49999821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16666610.

The product of its digits is 419904, while the sum is 51.

The square root of 49999821 is about 7071.0551546428. The cubic root of 49999821 is about 368.4027102358.

The spelling of 49999821 in words is "forty-nine million, nine hundred ninety-nine thousand, eight hundred twenty-one".