49721681 has 4 divisors (see below), whose sum is σ = 49864500. Its totient is φ = 49578864.

The previous prime is 49721671. The next prime is 49721701. The reversal of 49721681 is 18612794.

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 27206656 + 22515025 = 5216^2 + 4745^2 .

It is a cyclic number.

It is not a de Polignac number, because 49721681 - 2¹⁸ = 49459537 is a prime.

It is a super-2 number, since 2×49721681² = 4944491122931522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (49721611) 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, 70886 + ... + 71583.

It is an arithmetic number, because the mean of its divisors is an integer number (12466125).

Almost surely, 2^49721681 is an apocalyptic number.

It is an amenable number.

49721681 is a deficient number, since it is larger than the sum of its proper divisors (142819).

49721681 is a wasteful number, since it uses less digits than its factorization.

49721681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142818.

The product of its digits is 24192, while the sum is 38.

The square root of 49721681 is about 7051.3602233895. The cubic root of 49721681 is about 367.7183203056.

The spelling of 49721681 in words is "forty-nine million, seven hundred twenty-one thousand, six hundred eighty-one".