61245349681 has 4 divisors (see below), whose sum is σ = 61290153792. Its totient is φ = 61200545572.

The previous prime is 61245349663. The next prime is 61245349691. The reversal of 61245349681 is 18694354216.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 61245349681 - 2⁷ = 61245349553 is a prime.

It is a super-2 number, since 2×61245349681² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61245349631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22400005 + ... + 22402738.

It is an arithmetic number, because the mean of its divisors is an integer number (15322538448).

Almost surely, 2^61245349681 is an apocalyptic number.

It is an amenable number.

61245349681 is a deficient number, since it is larger than the sum of its proper divisors (44804111).

61245349681 is a wasteful number, since it uses less digits than its factorization.

61245349681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44804110.

The product of its digits is 1244160, while the sum is 49.

The spelling of 61245349681 in words is "sixty-one billion, two hundred forty-five million, three hundred forty-nine thousand, six hundred eighty-one".