1972161 has 8 divisors (see below), whose sum is σ = 2921760. Its totient is φ = 1314756.

The previous prime is 1972147. The next prime is 1972169. The reversal of 1972161 is 1612791.

It is not a de Polignac number, because 1972161 - 2⁵ = 1972129 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 73043 = 1972161 / (1 + 9 + 7 + 2 + 1 + 6 + 1).

It is not an unprimeable number, because it can be changed into a prime (1972169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36495 + ... + 36548.

It is an arithmetic number, because the mean of its divisors is an integer number (365220).

2^1972161 is an apocalyptic number.

It is an amenable number.

1972161 is a deficient number, since it is larger than the sum of its proper divisors (949599).

1972161 is an equidigital number, since it uses as much as digits as its factorization.

1972161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73052 (or 73046 counting only the distinct ones).

The product of its digits is 756, while the sum is 27.

The square root of 1972161 is about 1404.3364981371. The cubic root of 1972161 is about 125.4047890847.

The spelling of 1972161 in words is "one million, nine hundred seventy-two thousand, one hundred sixty-one".