97661891819 has 8 divisors (see below), whose sum is σ = 99219954960. Its totient is φ = 96115078656.

The previous prime is 97661891783. The next prime is 97661891861. The reversal of 97661891819 is 91819816679.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-97661891819 is a prime.

It is a super-2 number, since 2×97661891819² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (97661891869) 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, 2794994 + ... + 2829719.

It is an arithmetic number, because the mean of its divisors is an integer number (12402494370).

Almost surely, 2^97661891819 is an apocalyptic number.

97661891819 is a deficient number, since it is larger than the sum of its proper divisors (1558063141).

97661891819 is a wasteful number, since it uses less digits than its factorization.

97661891819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5624989.

The product of its digits is 11757312, while the sum is 65.

The spelling of 97661891819 in words is "ninety-seven billion, six hundred sixty-one million, eight hundred ninety-one thousand, eight hundred nineteen".