19187141977969 has 45 divisors (see below), whose sum is σ = 22862725760637. Its totient is φ = 16055494142688.

The previous prime is 19187141977931. The next prime is 19187141977979. The reversal of 19187141977969 is 96977914178191.

The square root of 19187141977969 is 4380313.

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

It can be written as a sum of positive squares in 2 ways, for example, as 7279673459569 + 11907468518400 = 2698087^2 + 3450720^2 .

It is not a de Polignac number, because 19187141977969 - 2⁷ = 19187141977841 is a prime.

It is a super-2 number, since 2×19187141977969² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (79).

It is not an unprimeable number, because it can be changed into a prime (19187141977919) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 215585864877 + ... + 215585864965.

Almost surely, 2^{19187141977969} is an apocalyptic number.

19187141977969 is the 4380313-rd square number.

19187141977969 is the 2190157-th centered octagonal number.

It is an amenable number.

19187141977969 is a deficient number, since it is larger than the sum of its proper divisors (3675583782668).

19187141977969 is an frugal number, since it uses more digits than its factorization.

19187141977969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528 (or 175 counting only the distinct ones).

The product of its digits is 432081216, while the sum is 79.

The spelling of 19187141977969 in words is "nineteen trillion, one hundred eighty-seven billion, one hundred forty-one million, nine hundred seventy-seven thousand, nine hundred sixty-nine".