1662719987 has 4 divisors (see below), whose sum is σ = 1698097056. Its totient is φ = 1627342920.

The previous prime is 1662719953. The next prime is 1662720019. The reversal of 1662719987 is 7899172661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1662719987 - 2¹² = 1662715891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1662719917) 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, 17688464 + ... + 17688557.

It is an arithmetic number, because the mean of its divisors is an integer number (424524264).

Almost surely, 2^1662719987 is an apocalyptic number.

1662719987 is a deficient number, since it is larger than the sum of its proper divisors (35377069).

1662719987 is an equidigital number, since it uses as much as digits as its factorization.

1662719987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35377068.

The product of its digits is 2286144, while the sum is 56.

The square root of 1662719987 is about 40776.4636401932. The cubic root of 1662719987 is about 1184.6945005823.

The spelling of 1662719987 in words is "one billion, six hundred sixty-two million, seven hundred nineteen thousand, nine hundred eighty-seven".