49997821 has 2 divisors, whose sum is σ = 49997822. Its totient is φ = 49997820.

The previous prime is 49997809. The next prime is 49997869. The reversal of 49997821 is 12879994.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27092025 + 22905796 = 5205^2 + 4786^2 .

It is a cyclic number.

It is not a de Polignac number, because 49997821 - 2⁹ = 49997309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (49997891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 24998910 + 24998911.

It is an arithmetic number, because the mean of its divisors is an integer number (24998911).

Almost surely, 2^49997821 is an apocalyptic number.

It is an amenable number.

49997821 is a deficient number, since it is larger than the sum of its proper divisors (1).

49997821 is an equidigital number, since it uses as much as digits as its factorization.

49997821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 49.

The square root of 49997821 is about 7070.9137316191. The cubic root of 49997821 is about 368.3977981165.

The spelling of 49997821 in words is "forty-nine million, nine hundred ninety-seven thousand, eight hundred twenty-one".