20181895969 has 9 divisors (see below), whose sum is σ = 21302855667. Its totient is φ = 19117133784.

The previous prime is 20181895957. The next prime is 20181895973. The reversal of 20181895969 is 96959818102.

The square root of 20181895969 is 142063.

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

It can be written as a sum of positive squares in only one way, i.e., 19316830225 + 865065744 = 138985^2 + 29412^2 .

It is not a de Polignac number, because 20181895969 - 2¹³ = 20181887777 is a prime.

It is a super-2 number, since 2×20181895969² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20181895919) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2695459 + ... + 2702935.

It is an arithmetic number, because the mean of its divisors is an integer number (2366983963).

Almost surely, 2^20181895969 is an apocalyptic number.

20181895969 is the 142063-rd square number.

20181895969 is the 71032-nd centered octagonal number.

It is an amenable number.

20181895969 is a deficient number, since it is larger than the sum of its proper divisors (1120959698).

20181895969 is an frugal number, since it uses more digits than its factorization.

20181895969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14992 (or 7496 counting only the distinct ones).

The product of its (nonzero) digits is 2799360, while the sum is 58.

The spelling of 20181895969 in words is "twenty billion, one hundred eighty-one million, eight hundred ninety-five thousand, nine hundred sixty-nine".