1951941500161 has 3 divisors (see below), whose sum is σ = 1951942897281. Its totient is φ = 1951940103042.

The previous prime is 1951941500147. The next prime is 1951941500183. The reversal of 1951941500161 is 1610051491591.

The square root of 1951941500161 is 1397119.

It is a perfect power (a square), and thus also a powerful 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.

It is not a de Polignac number, because 1951941500161 - 2⁵ = 1951941500129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1951941500141) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 698560 + ... + 2095678.

It is an arithmetic number, because the mean of its divisors is an integer number (650647632427).

Almost surely, 2^{1951941500161} is an apocalyptic number.

1951941500161 is the 1397119-th square number.

1951941500161 is the 698560-th centered octagonal number.

It is an amenable number.

1951941500161 is a deficient number, since it is larger than the sum of its proper divisors (1397120).

1951941500161 is an frugal number, since it uses more digits than its factorization.

1951941500161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2794238 (or 1397119 counting only the distinct ones).

The product of its (nonzero) digits is 48600, while the sum is 43.

The spelling of 1951941500161 in words is "one trillion, nine hundred fifty-one billion, nine hundred forty-one million, five hundred thousand, one hundred sixty-one".