1651661566 has 8 divisors (see below), whose sum is σ = 2486913264. Its totient is φ = 822690480.

The previous prime is 1651661551. The next prime is 1651661581. The reversal of 1651661566 is 6651661561.

It is an interprime number because it is at equal distance from previous prime (1651661551) and next prime (1651661581).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1569495 + ... + 1570546.

It is an arithmetic number, because the mean of its divisors is an integer number (310864158).

Almost surely, 2^1651661566 is an apocalyptic number.

1651661566 is a deficient number, since it is larger than the sum of its proper divisors (835251698).

1651661566 is a wasteful number, since it uses less digits than its factorization.

1651661566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3140306.

The product of its digits is 194400, while the sum is 43.

The square root of 1651661566 is about 40640.6393404435. The cubic root of 1651661566 is about 1182.0622670217.

The spelling of 1651661566 in words is "one billion, six hundred fifty-one million, six hundred sixty-one thousand, five hundred sixty-six".