21318044049 has 15 divisors (see below), whose sum is σ = 31847436313. Its totient is φ = 14211153324.

The previous prime is 21318043993. The next prime is 21318044107. The reversal of 21318044049 is 94044081312.

It is a happy number.

The square root of 21318044049 is 146007.

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

21318044049 is a `hidden beast` number, since 2 + 131 + 80 + 440 + 4 + 9 = 666.

It is not a de Polignac number, because 21318044049 - 2¹¹ = 21318042001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21318044549) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 1305952 + ... + 1322174.

Almost surely, 2^21318044049 is an apocalyptic number.

21318044049 is the 146007-th square number.

21318044049 is the 73004-th centered octagonal number.

It is an amenable number.

21318044049 is a deficient number, since it is larger than the sum of its proper divisors (10529392264).

21318044049 is an frugal number, since it uses more digits than its factorization.

21318044049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32458 (or 16226 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

Multiplying 21318044049 by its sum of digits (36), we get a square (767449585764 = 876042²).

The spelling of 21318044049 in words is "twenty-one billion, three hundred eighteen million, forty-four thousand, forty-nine".