81259628690 has 16 divisors (see below), whose sum is σ = 149379403392. Its totient is φ = 31812279984.

The previous prime is 81259628689. The next prime is 81259628711. The reversal of 81259628690 is 9682695218.

It is a super-2 number, since 2×81259628690² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 86445944 + ... + 86446883.

It is an arithmetic number, because the mean of its divisors is an integer number (9336212712).

Almost surely, 2^81259628690 is an apocalyptic number.

81259628690 is a deficient number, since it is larger than the sum of its proper divisors (68119774702).

81259628690 is a wasteful number, since it uses less digits than its factorization.

81259628690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172892881.

The product of its (nonzero) digits is 3732480, while the sum is 56.

The spelling of 81259628690 in words is "eighty-one billion, two hundred fifty-nine million, six hundred twenty-eight thousand, six hundred ninety".