19802161 has 16 divisors (see below), whose sum is σ = 22325760. Its totient is φ = 17452800.

The previous prime is 19802137. The next prime is 19802171. The reversal of 19802161 is 16120891.

It is a happy number.

It is not a de Polignac number, because 19802161 - 2⁵ = 19802129 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19802131) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32320 + ... + 32926.

It is an arithmetic number, because the mean of its divisors is an integer number (1395360).

Almost surely, 2^19802161 is an apocalyptic number.

It is an amenable number.

19802161 is a deficient number, since it is larger than the sum of its proper divisors (2523599).

19802161 is a wasteful number, since it uses less digits than its factorization.

19802161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 744.

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 19802161 is about 4449.9619099493. The cubic root of 19802161 is about 270.5437646931.

The spelling of 19802161 in words is "nineteen million, eight hundred two thousand, one hundred sixty-one".