1691066745 has 24 divisors (see below), whose sum is σ = 2934155016. Its totient is φ = 900987648.

The previous prime is 1691066731. The next prime is 1691066803. The reversal of 1691066745 is 5476601961.

It can be written as a sum of positive squares in 4 ways, for example, as 72131049 + 1618935696 = 8493^2 + 40236^2 .

It is not a de Polignac number, because 1691066745 - 2⁹ = 1691066233 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 1691066745.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27037 + ... + 64133.

It is an arithmetic number, because the mean of its divisors is an integer number (122256459).

Almost surely, 2^1691066745 is an apocalyptic number.

1691066745 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1691066745 is a deficient number, since it is larger than the sum of its proper divisors (1243088271).

1691066745 is a wasteful number, since it uses less digits than its factorization.

1691066745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38121 (or 38118 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 45.

The square root of 1691066745 is about 41122.5819349904. The cubic root of 1691066745 is about 1191.3889920023.

The spelling of 1691066745 in words is "one billion, six hundred ninety-one million, sixty-six thousand, seven hundred forty-five".