501661001155 has 4 divisors (see below), whose sum is σ = 601993201392. Its totient is φ = 401328800920.

The previous prime is 501661001137. The next prime is 501661001209. The reversal of 501661001155 is 551100166105.

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

It is not a de Polignac number, because 501661001155 - 2¹⁷ = 501660870083 is a prime.

It is a super-2 number, since 2×501661001155² (a number of 24 digits) contains 22 as substring.

It is a Duffinian 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, 50166100111 + ... + 50166100120.

It is an arithmetic number, because the mean of its divisors is an integer number (150498300348).

Almost surely, 2^501661001155 is an apocalyptic number.

501661001155 is a deficient number, since it is larger than the sum of its proper divisors (100332200237).

501661001155 is a wasteful number, since it uses less digits than its factorization.

501661001155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100332200236.

The product of its (nonzero) digits is 4500, while the sum is 31.

The spelling of 501661001155 in words is "five hundred one billion, six hundred sixty-one million, one thousand, one hundred fifty-five".