49911581281 has 9 divisors (see below), whose sum is σ = 51168018873. Its totient is φ = 48685289280.

The previous prime is 49911581233. The next prime is 49911581287. The reversal of 49911581281 is 18218511994.

The square root of 49911581281 is 223409.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 36343990881 + 13567590400 = 190641^2 + 116480^2 .

It is a de Polignac number, because none of the positive numbers 2^k-49911581281 is a prime.

It is a super-2 number, since 2×49911581281² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (49911581287) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 9157045 + ... + 9162493.

Almost surely, 2^49911581281 is an apocalyptic number.

49911581281 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

49911581281 is the 223409-th square number.

49911581281 is the 111705-th centered octagonal number.

It is an amenable number.

49911581281 is a deficient number, since it is larger than the sum of its proper divisors (1256437592).

49911581281 is an frugal number, since it uses more digits than its factorization.

49911581281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10980 (or 5490 counting only the distinct ones).

The product of its digits is 207360, while the sum is 49.

Multiplying 49911581281 by its sum of digits (49), we get a square (2445667482769 = 1563863²).

The spelling of 49911581281 in words is "forty-nine billion, nine hundred eleven million, five hundred eighty-one thousand, two hundred eighty-one".