81962641 has 4 divisors (see below), whose sum is σ = 83186032. Its totient is φ = 80739252.

The previous prime is 81962633. The next prime is 81962653. The reversal of 81962641 is 14626918.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 14626918 = 2 ⋅7313459.

It is a cyclic number.

It is not a de Polignac number, because 81962641 - 2³ = 81962633 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81962641.

It is not an unprimeable number, because it can be changed into a prime (81912641) 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, 611595 + ... + 611728.

It is an arithmetic number, because the mean of its divisors is an integer number (20796508).

Almost surely, 2^81962641 is an apocalyptic number.

It is an amenable number.

81962641 is a deficient number, since it is larger than the sum of its proper divisors (1223391).

81962641 is a wasteful number, since it uses less digits than its factorization.

81962641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1223390.

The product of its digits is 20736, while the sum is 37.

The square root of 81962641 is about 9053.3220974403. The cubic root of 81962641 is about 434.3821607156.

The spelling of 81962641 in words is "eighty-one million, nine hundred sixty-two thousand, six hundred forty-one".