20154300561 has 6 divisors (see below), whose sum is σ = 29111767490. Its totient is φ = 13436200368.

The previous prime is 20154300553. The next prime is 20154300583. The reversal of 20154300561 is 16500345102.

20154300561 is a `hidden beast` number, since 20 + 1 + 54 + 30 + 0 + 561 = 666.

It can be written as a sum of positive squares in only one way, i.e., 18507969936 + 1646330625 = 136044^2 + 40575^2 .

It is not a de Polignac number, because 20154300561 - 2³ = 20154300553 is a prime.

It is a super-2 number, since 2×20154300561² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20154300161) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1119683356 + ... + 1119683373.

Almost surely, 2^20154300561 is an apocalyptic number.

It is an amenable number.

20154300561 is a deficient number, since it is larger than the sum of its proper divisors (8957466929).

20154300561 is a wasteful number, since it uses less digits than its factorization.

20154300561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2239366735 (or 2239366732 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

Adding to 20154300561 its reverse (16500345102), we get a palindrome (36654645663).

The spelling of 20154300561 in words is "twenty billion, one hundred fifty-four million, three hundred thousand, five hundred sixty-one".