1691252061 has 4 divisors (see below), whose sum is σ = 2255002752. Its totient is φ = 1127501372.

The previous prime is 1691252053. The next prime is 1691252071. The reversal of 1691252061 is 1602521961.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1691252061 - 2³ = 1691252053 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1691252071) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 281875341 + ... + 281875346.

It is an arithmetic number, because the mean of its divisors is an integer number (563750688).

Almost surely, 2^1691252061 is an apocalyptic number.

It is an amenable number.

1691252061 is a deficient number, since it is larger than the sum of its proper divisors (563750691).

1691252061 is an equidigital number, since it uses as much as digits as its factorization.

1691252061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 563750690.

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 1691252061 is about 41124.8350878152. The cubic root of 1691252061 is about 1191.4325099728.

The spelling of 1691252061 in words is "one billion, six hundred ninety-one million, two hundred fifty-two thousand, sixty-one".