52161981 has 16 divisors (see below), whose sum is σ = 72658560. Its totient is φ = 33243840.

The previous prime is 52161961. The next prime is 52161997. The reversal of 52161981 is 18916125.

It is not a de Polignac number, because 52161981 - 2¹³ = 52153789 is a prime.

It is a super-2 number, since 2×52161981² = 5441744523688722, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (52161961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6051 + ... + 11871.

It is an arithmetic number, because the mean of its divisors is an integer number (4541160).

Almost surely, 2^52161981 is an apocalyptic number.

It is an amenable number.

52161981 is a deficient number, since it is larger than the sum of its proper divisors (20496579).

52161981 is a wasteful number, since it uses less digits than its factorization.

52161981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5956.

The product of its digits is 4320, while the sum is 33.

The square root of 52161981 is about 7222.3251796080. The cubic root of 52161981 is about 373.6382754240.

The spelling of 52161981 in words is "fifty-two million, one hundred sixty-one thousand, nine hundred eighty-one".