1155890001 has 32 divisors (see below), whose sum is σ = 1861263360. Its totient is φ = 623772864.

The previous prime is 1155889979. The next prime is 1155890003. The reversal of 1155890001 is 1000985511.

It is not a de Polignac number, because 1155890001 - 2¹⁵ = 1155857233 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1155890003) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 23011 + ... + 53303.

It is an arithmetic number, because the mean of its divisors is an integer number (58164480).

Almost surely, 2^1155890001 is an apocalyptic number.

It is an amenable number.

1155890001 is a deficient number, since it is larger than the sum of its proper divisors (705373359).

1155890001 is a wasteful number, since it uses less digits than its factorization.

1155890001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30405.

The product of its (nonzero) digits is 1800, while the sum is 30.

The square root of 1155890001 is about 33998.3823291638. The cubic root of 1155890001 is about 1049.4751726370.

The spelling of 1155890001 in words is "one billion, one hundred fifty-five million, eight hundred ninety thousand, one".