40561557201 has 81 divisors (see below), whose sum is σ = 68601510523. Its totient is φ = 23072269440.

The previous prime is 40561557187. The next prime is 40561557203. The reversal of 40561557201 is 10275516504.

The square root of 40561557201 is 201399.

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

40561557201 is a `hidden beast` number, since 40 + 5 + 61 + 557 + 2 + 0 + 1 = 666.

40561557201 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 31579067025 + 8982490176 = 177705^2 + 94776^2 .

It is not a de Polignac number, because 40561557201 - 2²⁵ = 40528002769 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (40561557203) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 112984660 + ... + 112985018.

Almost surely, 2^40561557201 is an apocalyptic number.

40561557201 is the 201399-th square number.

40561557201 is the 100700-th centered octagonal number.

It is an amenable number.

40561557201 is a deficient number, since it is larger than the sum of its proper divisors (28039953322).

40561557201 is a wasteful number, since it uses less digits than its factorization.

40561557201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 780 (or 390 counting only the distinct ones).

The product of its (nonzero) digits is 42000, while the sum is 36.

Multiplying 40561557201 by its sum of digits (36), we get a square (1460216059236 = 1208394²).

The spelling of 40561557201 in words is "forty billion, five hundred sixty-one million, five hundred fifty-seven thousand, two hundred one".