61785007221 has 16 divisors (see below), whose sum is σ = 95340339200. Its totient is φ = 34858809648.

The previous prime is 61785007127. The next prime is 61785007243. The reversal of 61785007221 is 12270058716.

61785007221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 61785007221 - 2³⁴ = 44605138037 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 61785007221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61785007121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18619501 + ... + 18622818.

It is an arithmetic number, because the mean of its divisors is an integer number (5958771200).

Almost surely, 2^61785007221 is an apocalyptic number.

It is an amenable number.

61785007221 is a deficient number, since it is larger than the sum of its proper divisors (33555331979).

61785007221 is a wasteful number, since it uses less digits than its factorization.

61785007221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37242408.

The product of its (nonzero) digits is 47040, while the sum is 39.

The spelling of 61785007221 in words is "sixty-one billion, seven hundred eighty-five million, seven thousand, two hundred twenty-one".