1921682569 has 9 divisors (see below), whose sum is σ = 1957440013. Its totient is φ = 1886569132.

The previous prime is 1921682549. The next prime is 1921682597. The reversal of 1921682569 is 9652861291.

The square root of 1921682569 is 43837.

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

It is not a de Polignac number, because 1921682569 - 2²¹ = 1919585417 is a prime.

It is a super-2 number, since 2×1921682569² = 7385727791996879522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1921682509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2586012 + ... + 2586754.

Almost surely, 2^1921682569 is an apocalyptic number.

1921682569 is the 43837-th square number.

1921682569 is the 21919-th centered octagonal number.

It is an amenable number.

1921682569 is a deficient number, since it is larger than the sum of its proper divisors (35757444).

1921682569 is an frugal number, since it uses more digits than its factorization.

1921682569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1604 (or 802 counting only the distinct ones).

The product of its digits is 466560, while the sum is 49.

The cubic root of 1921682569 is about 1243.2559611753.

Multiplying 1921682569 by its sum of digits (49), we get a square (94162445881 = 306859²).

The spelling of 1921682569 in words is "one billion, nine hundred twenty-one million, six hundred eighty-two thousand, five hundred sixty-nine".