61421823865 has 8 divisors (see below), whose sum is σ = 75503900808. Its totient is φ = 47938984320.

The previous prime is 61421823857. The next prime is 61421823893. The reversal of 61421823865 is 56832812416.

It can be written as a sum of positive squares in 4 ways, for example, as 5659251984 + 55762571881 = 75228^2 + 236141^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 61421823865 - 2³ = 61421823857 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 149809122 + ... + 149809531.

It is an arithmetic number, because the mean of its divisors is an integer number (9437987601).

Almost surely, 2^61421823865 is an apocalyptic number.

It is an amenable number.

61421823865 is a deficient number, since it is larger than the sum of its proper divisors (14082076943).

61421823865 is a wasteful number, since it uses less digits than its factorization.

61421823865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299618699.

The product of its digits is 552960, while the sum is 46.

The spelling of 61421823865 in words is "sixty-one billion, four hundred twenty-one million, eight hundred twenty-three thousand, eight hundred sixty-five".