61257771985 has 16 divisors (see below), whose sum is σ = 76215867840. Its totient is φ = 47209489600.

The previous prime is 61257771979. The next prime is 61257772003. The reversal of 61257771985 is 58917775216.

It is not a de Polignac number, because 61257771985 - 2¹³ = 61257763793 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 412591 + ... + 541060.

It is an arithmetic number, because the mean of its divisors is an integer number (4763491740).

Almost surely, 2^61257771985 is an apocalyptic number.

It is an amenable number.

61257771985 is a deficient number, since it is larger than the sum of its proper divisors (14958095855).

61257771985 is a wasteful number, since it uses less digits than its factorization.

61257771985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 954128.

The product of its digits is 7408800, while the sum is 58.

The spelling of 61257771985 in words is "sixty-one billion, two hundred fifty-seven million, seven hundred seventy-one thousand, nine hundred eighty-five".