49997781 has 12 divisors (see below), whose sum is σ = 72409740. Its totient is φ = 33243840.

The previous prime is 49997771. The next prime is 49997803. The reversal of 49997781 is 18779994.

49997781 is a `hidden beast` number, since 499 + 9 + 77 + 81 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 3294225 + 46703556 = 1815^2 + 6834^2 .

It is not a de Polignac number, because 49997781 - 2¹⁰ = 49996757 is a prime.

It is a super-2 number, since 2×49997781² = 4999556209847922, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (49997771) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3640 + ... + 10641.

It is an arithmetic number, because the mean of its divisors is an integer number (6034145).

Almost surely, 2^49997781 is an apocalyptic number.

It is an amenable number.

49997781 is a deficient number, since it is larger than the sum of its proper divisors (22411959).

49997781 is a wasteful number, since it uses less digits than its factorization.

49997781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14676 (or 14673 counting only the distinct ones).

The product of its digits is 1143072, while the sum is 54.

The square root of 49997781 is about 7070.9109031298. The cubic root of 49997781 is about 368.3976998728.

The spelling of 49997781 in words is "forty-nine million, nine hundred ninety-seven thousand, seven hundred eighty-one".