140561821 has 4 divisors (see below), whose sum is σ = 141634944. Its totient is φ = 139488700.

The previous prime is 140561807. The next prime is 140561833. The reversal of 140561821 is 128165041.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 128165041 = 11321².

It is a cyclic number.

It is not a de Polignac number, because 140561821 - 2⁵ = 140561789 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 140561821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (140561851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 536365 + ... + 536626.

It is an arithmetic number, because the mean of its divisors is an integer number (35408736).

Almost surely, 2^140561821 is an apocalyptic number.

It is an amenable number.

140561821 is a deficient number, since it is larger than the sum of its proper divisors (1073123).

140561821 is a wasteful number, since it uses less digits than its factorization.

140561821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1073122.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 140561821 is about 11855.8770658269. The cubic root of 140561821 is about 519.9430669917.

The spelling of 140561821 in words is "one hundred forty million, five hundred sixty-one thousand, eight hundred twenty-one".