191099220642 has 486 divisors, whose sum is σ = 528442519059. Its totient is φ = 49853422080.

The previous prime is 191099220607. The next prime is 191099220677. The reversal of 191099220642 is 246022990191.

It is an interprime number because it is at equal distance from previous prime (191099220607) and next prime (191099220677).

It can be written as a sum of positive squares in 5 ways, for example, as 152584765641 + 38514455001 = 390621^2 + 196251^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=309111.

It is an unprimeable number.

It is a polite number, since it can be written in 242 ways as a sum of consecutive naturals, for example, 6589628284 + ... + 6589628312.

Almost surely, 2^191099220642 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 191099220642

191099220642 is an abundant number, since it is smaller than the sum of its proper divisors (337343298417).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

191099220642 is a wasteful number, since it uses less digits than its factorization.

191099220642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160 (or 81 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 45.

The spelling of 191099220642 in words is "one hundred ninety-one billion, ninety-nine million, two hundred twenty thousand, six hundred forty-two".