61861140961 has 3 divisors (see below), whose sum is σ = 61861389681. Its totient is φ = 61860892242.

The previous prime is 61861140959. The next prime is 61861140989. The reversal of 61861140961 is 16904116816.

The square root of 61861140961 is 248719.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 61861140961 - 2¹ = 61861140959 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61861140361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 124360 + ... + 373078.

It is an arithmetic number, because the mean of its divisors is an integer number (20620463227).

Almost surely, 2^61861140961 is an apocalyptic number.

61861140961 is the 248719-th square number.

61861140961 is the 124360-th centered octagonal number.

It is an amenable number.

61861140961 is a deficient number, since it is larger than the sum of its proper divisors (248720).

61861140961 is an frugal number, since it uses more digits than its factorization.

61861140961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 497438 (or 248719 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 43.

The spelling of 61861140961 in words is "sixty-one billion, eight hundred sixty-one million, one hundred forty thousand, nine hundred sixty-one".