1665401155 has 16 divisors (see below), whose sum is σ = 2193548544. Its totient is φ = 1203763680.

The previous prime is 1665401147. The next prime is 1665401219. The reversal of 1665401155 is 5511045661.

It is not a de Polignac number, because 1665401155 - 2³ = 1665401147 is a prime.

It is a super-2 number, since 2×1665401155² = 5547122014150668050, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1665401155.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 83919 + ... + 101848.

It is an arithmetic number, because the mean of its divisors is an integer number (137096784).

Almost surely, 2^1665401155 is an apocalyptic number.

1665401155 is a deficient number, since it is larger than the sum of its proper divisors (528147389).

1665401155 is a wasteful number, since it uses less digits than its factorization.

1665401155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185946.

The product of its (nonzero) digits is 18000, while the sum is 34.

The square root of 1665401155 is about 40809.3268138547. The cubic root of 1665401155 is about 1185.3309395139.

The spelling of 1665401155 in words is "one billion, six hundred sixty-five million, four hundred one thousand, one hundred fifty-five".