1691469977 has 4 divisors (see below), whose sum is σ = 1694294400. Its totient is φ = 1688645556.

The previous prime is 1691469953. The next prime is 1691470057. The reversal of 1691469977 is 7799641961.

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, and also an emirpimes, since its reverse is a distinct semiprime: 7799641961 = 761 ⋅10249201.

It is a cyclic number.

It is not a de Polignac number, because 1691469977 - 2⁸ = 1691469721 is a prime.

It is a super-2 number, since 2×1691469977² = 5722141366184761058, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1691469907) 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, 1411313 + ... + 1412510.

It is an arithmetic number, because the mean of its divisors is an integer number (423573600).

Almost surely, 2^1691469977 is an apocalyptic number.

It is an amenable number.

1691469977 is a deficient number, since it is larger than the sum of its proper divisors (2824423).

1691469977 is an equidigital number, since it uses as much as digits as its factorization.

1691469977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2824422.

The product of its digits is 5143824, while the sum is 59.

The square root of 1691469977 is about 41127.4844477510. The cubic root of 1691469977 is about 1191.4836793722.

The spelling of 1691469977 in words is "one billion, six hundred ninety-one million, four hundred sixty-nine thousand, nine hundred seventy-seven".