61397958917 has 4 divisors (see below), whose sum is σ = 61551071436. Its totient is φ = 61244846400.

The previous prime is 61397958901. The next prime is 61397959003. The reversal of 61397958917 is 71985979316.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 60798737476 + 599221441 = 246574^2 + 24479^2 .

It is a cyclic number.

It is not a de Polignac number, because 61397958917 - 2⁴ = 61397958901 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 (61397858917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76555658 + ... + 76556459.

It is an arithmetic number, because the mean of its divisors is an integer number (15387767859).

Almost surely, 2^61397958917 is an apocalyptic number.

It is an amenable number.

61397958917 is a deficient number, since it is larger than the sum of its proper divisors (153112519).

61397958917 is a wasteful number, since it uses less digits than its factorization.

61397958917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153112518.

The product of its digits is 25719120, while the sum is 65.

The spelling of 61397958917 in words is "sixty-one billion, three hundred ninety-seven million, nine hundred fifty-eight thousand, nine hundred seventeen".