61845551347221 has 8 divisors (see below), whose sum is σ = 91623039032960. Its totient is φ = 41230367564796.

The previous prime is 61845551347171. The next prime is 61845551347247. The reversal of 61845551347221 is 12274315554816.

61845551347221 is a `hidden beast` number, since 6 + 1 + 8 + 4 + 55 + 513 + 4 + 72 + 2 + 1 = 666.

It is not a de Polignac number, because 61845551347221 - 2¹⁵ = 61845551314453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61845551342221) 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, 1145287987885 + ... + 1145287987938.

It is an arithmetic number, because the mean of its divisors is an integer number (11452879879120).

Almost surely, 2^{61845551347221} is an apocalyptic number.

It is an amenable number.

61845551347221 is a deficient number, since it is larger than the sum of its proper divisors (29777487685739).

61845551347221 is a wasteful number, since it uses less digits than its factorization.

61845551347221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2290575975832 (or 2290575975826 counting only the distinct ones).

The product of its digits is 8064000, while the sum is 54.

The spelling of 61845551347221 in words is "sixty-one trillion, eight hundred forty-five billion, five hundred fifty-one million, three hundred forty-seven thousand, two hundred twenty-one".