140636561 has 8 divisors (see below), whose sum is σ = 152353320. Its totient is φ = 129816336.

The previous prime is 140636557. The next prime is 140636579. The reversal of 140636561 is 165636041.

It can be written as a sum of positive squares in 4 ways, for example, as 5612161 + 135024400 = 2369^2 + 11620^2 .

It is not a de Polignac number, because 140636561 - 2² = 140636557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (140636521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29810 + ... + 34203.

It is an arithmetic number, because the mean of its divisors is an integer number (19044165).

Almost surely, 2^140636561 is an apocalyptic number.

It is an amenable number.

140636561 is a deficient number, since it is larger than the sum of its proper divisors (11716759).

140636561 is an frugal number, since it uses more digits than its factorization.

140636561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64052 (or 64026 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 140636561 is about 11859.0286701736. The cubic root of 140636561 is about 520.0352059497.

The spelling of 140636561 in words is "one hundred forty million, six hundred thirty-six thousand, five hundred sixty-one".