2155945971 has 8 divisors (see below), whose sum is σ = 2886932880. Its totient is φ = 1431128192.

The previous prime is 2155945969. The next prime is 2155945973. The reversal of 2155945971 is 1795495512.

It is an interprime number because it is at equal distance from previous prime (2155945969) and next prime (2155945973).

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

It is a cyclic number.

It is not a de Polignac number, because 2155945971 - 2¹ = 2155945969 is a prime.

It is a super-2 number, since 2×2155945971² = 9296206059742265682, 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 2155945971.

It is not an unprimeable number, because it can be changed into a prime (2155945973) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1541466 + ... + 1542863.

It is an arithmetic number, because the mean of its divisors is an integer number (360866610).

Almost surely, 2^2155945971 is an apocalyptic number.

2155945971 is a deficient number, since it is larger than the sum of its proper divisors (730986909).

2155945971 is a wasteful number, since it uses less digits than its factorization.

2155945971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3084565.

The product of its digits is 567000, while the sum is 48.

The square root of 2155945971 is about 46432.1652628865. The cubic root of 2155945971 is about 1291.8515908075.

The spelling of 2155945971 in words is "two billion, one hundred fifty-five million, nine hundred forty-five thousand, nine hundred seventy-one".