81952141 has 4 divisors (see below), whose sum is σ = 81970300. Its totient is φ = 81933984.

The previous prime is 81952139. The next prime is 81952147. The reversal of 81952141 is 14125918.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 51194025 + 30758116 = 7155^2 + 5546^2 .

It is a cyclic number.

It is not a de Polignac number, because 81952141 - 2¹ = 81952139 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81952147) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3505 + ... + 13273.

It is an arithmetic number, because the mean of its divisors is an integer number (20492575).

Almost surely, 2^81952141 is an apocalyptic number.

It is an amenable number.

81952141 is a deficient number, since it is larger than the sum of its proper divisors (18159).

81952141 is an equidigital number, since it uses as much as digits as its factorization.

81952141 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18158.

The product of its digits is 2880, while the sum is 31.

The square root of 81952141 is about 9052.7421812399. The cubic root of 81952141 is about 434.3636107705.

The spelling of 81952141 in words is "eighty-one million, nine hundred fifty-two thousand, one hundred forty-one".