81946625061 has 16 divisors (see below), whose sum is σ = 127227106944. Its totient is φ = 45943120704.

The previous prime is 81946625051. The next prime is 81946625071. The reversal of 81946625061 is 16052664918.

It is an interprime number because it is at equal distance from previous prime (81946625051) and next prime (81946625071).

It is not a de Polignac number, because 81946625061 - 2²³ = 81938236453 is a prime.

It is a super-2 number, since 2×81946625061² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81946625061.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81946625041) 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, 36812286 + ... + 36814511.

It is an arithmetic number, because the mean of its divisors is an integer number (7951694184).

Almost surely, 2^81946625061 is an apocalyptic number.

It is an amenable number.

81946625061 is a deficient number, since it is larger than the sum of its proper divisors (45280481883).

81946625061 is a wasteful number, since it uses less digits than its factorization.

81946625061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73626860.

The product of its (nonzero) digits is 622080, while the sum is 48.

The spelling of 81946625061 in words is "eighty-one billion, nine hundred forty-six million, six hundred twenty-five thousand, sixty-one".