1659621079 has 2 divisors, whose sum is σ = 1659621080. Its totient is φ = 1659621078.

The previous prime is 1659621071. The next prime is 1659621121. The reversal of 1659621079 is 9701269561.

It is a weak prime.

It is an emirp because it is prime and its reverse (9701269561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1659621079 - 2³ = 1659621071 is a prime.

It is a super-2 number, since 2×1659621079² = 5508684251722248482, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1659621071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 829810539 + 829810540.

It is an arithmetic number, because the mean of its divisors is an integer number (829810540).

Almost surely, 2^1659621079 is an apocalyptic number.

1659621079 is a deficient number, since it is larger than the sum of its proper divisors (1).

1659621079 is an equidigital number, since it uses as much as digits as its factorization.

1659621079 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 204120, while the sum is 46.

The square root of 1659621079 is about 40738.4471844473. The cubic root of 1659621079 is about 1183.9580481754.

It can be divided in two parts, 16596 and 21079, that added together give a triangular number (37675 = T₂₇₄).

The spelling of 1659621079 in words is "one billion, six hundred fifty-nine million, six hundred twenty-one thousand, seventy-nine".