81954940525 has 12 divisors (see below), whose sum is σ = 101641699872. Its totient is φ = 65552614640.

The previous prime is 81954940519. The next prime is 81954940531. The reversal of 81954940525 is 52504945918.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81954940519) and next prime (81954940531).

It is not a de Polignac number, because 81954940525 - 2³ = 81954940517 is a prime.

It is a super-2 number, since 2×81954940525² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 134449 + ... + 426598.

It is an arithmetic number, because the mean of its divisors is an integer number (8470141656).

Almost surely, 2^81954940525 is an apocalyptic number.

It is an amenable number.

81954940525 is a deficient number, since it is larger than the sum of its proper divisors (19686759347).

81954940525 is a wasteful number, since it uses less digits than its factorization.

81954940525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 566900 (or 566895 counting only the distinct ones).

The product of its (nonzero) digits is 2592000, while the sum is 52.

The spelling of 81954940525 in words is "eighty-one billion, nine hundred fifty-four million, nine hundred forty thousand, five hundred twenty-five".