81931945070 has 16 divisors (see below), whose sum is σ = 152234840448. Its totient is φ = 31715591520.

The previous prime is 81931945061. The next prime is 81931945079. The reversal of 81931945070 is 7054913918.

It is an interprime number because it is at equal distance from previous prime (81931945061) and next prime (81931945079).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81931945079) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 132147989 + ... + 132148608.

It is an arithmetic number, because the mean of its divisors is an integer number (9514677528).

Almost surely, 2^81931945070 is an apocalyptic number.

81931945070 is a deficient number, since it is larger than the sum of its proper divisors (70302895378).

81931945070 is a wasteful number, since it uses less digits than its factorization.

81931945070 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264296635.

The product of its (nonzero) digits is 272160, while the sum is 47.

The spelling of 81931945070 in words is "eighty-one billion, nine hundred thirty-one million, nine hundred forty-five thousand, seventy".