161953947101 has 4 divisors (see below), whose sum is σ = 161954765532. Its totient is φ = 161953128672.

The previous prime is 161953947091. The next prime is 161953947151. The reversal of 161953947101 is 101749359161.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 101749359161 = 211 ⋅482224451.

It can be written as a sum of positive squares in 2 ways, for example, as 70886400025 + 91067547076 = 266245^2 + 301774^2 .

It is a cyclic number.

It is not a de Polignac number, because 161953947101 - 2¹⁴ = 161953930717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161953947151) 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, 93335 + ... + 576731.

It is an arithmetic number, because the mean of its divisors is an integer number (40488691383).

Almost surely, 2^161953947101 is an apocalyptic number.

It is an amenable number.

161953947101 is a deficient number, since it is larger than the sum of its proper divisors (818431).

161953947101 is an equidigital number, since it uses as much as digits as its factorization.

161953947101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 818430.

The product of its (nonzero) digits is 204120, while the sum is 47.

The spelling of 161953947101 in words is "one hundred sixty-one billion, nine hundred fifty-three million, nine hundred forty-seven thousand, one hundred one".