81520083020711 has 4 divisors (see below), whose sum is σ = 82281952955592. Its totient is φ = 80758213085832.

The previous prime is 81520083020699. The next prime is 81520083020741. The reversal of 81520083020711 is 11702038002518.

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

It is a cyclic number.

It is not a de Polignac number, because 81520083020711 - 2¹⁸ = 81520082758567 is a prime.

It is a super-2 number, since 2×81520083020711² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81520083020741) 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, 380934967280 + ... + 380934967493.

It is an arithmetic number, because the mean of its divisors is an integer number (20570488238898).

Almost surely, 2^{81520083020711} is an apocalyptic number.

81520083020711 is a deficient number, since it is larger than the sum of its proper divisors (761869934881).

81520083020711 is a wasteful number, since it uses less digits than its factorization.

81520083020711 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 761869934880.

The product of its (nonzero) digits is 26880, while the sum is 38.

The spelling of 81520083020711 in words is "eighty-one trillion, five hundred twenty billion, eighty-three million, twenty thousand, seven hundred eleven".