61255781145 has 64 divisors (see below), whose sum is σ = 117403050240. Its totient is φ = 30124030464.

The previous prime is 61255781137. The next prime is 61255781219. The reversal of 61255781145 is 54118755216.

61255781145 is a `hidden beast` number, since 6 + 1 + 2 + 557 + 81 + 14 + 5 = 666.

It is not a de Polignac number, because 61255781145 - 2³ = 61255781137 is a prime.

It is a super-2 number, since 2×61255781145² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 61255781145.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1643557 + ... + 1680413.

It is an arithmetic number, because the mean of its divisors is an integer number (1834422660).

Almost surely, 2^61255781145 is an apocalyptic number.

61255781145 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

61255781145 is a deficient number, since it is larger than the sum of its proper divisors (56147269095).

61255781145 is a wasteful number, since it uses less digits than its factorization.

61255781145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37831 (or 37825 counting only the distinct ones).

The product of its digits is 336000, while the sum is 45.

The spelling of 61255781145 in words is "sixty-one billion, two hundred fifty-five million, seven hundred eighty-one thousand, one hundred forty-five".