81405436570 has 16 divisors (see below), whose sum is σ = 146843562528. Its totient is φ = 32492446480.

The previous prime is 81405436543. The next prime is 81405436577. The reversal of 81405436570 is 7563450418.

It is not an unprimeable number, because it can be changed into a prime (81405436577) 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, 8711116 + ... + 8720455.

It is an arithmetic number, because the mean of its divisors is an integer number (9177722658).

Almost surely, 2^81405436570 is an apocalyptic number.

81405436570 is a deficient number, since it is larger than the sum of its proper divisors (65438125958).

81405436570 is a wasteful number, since it uses less digits than its factorization.

81405436570 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17432045.

The product of its (nonzero) digits is 403200, while the sum is 43.

Adding to 81405436570 its reverse (7563450418), we get a palindrome (88968886988).

The spelling of 81405436570 in words is "eighty-one billion, four hundred five million, four hundred thirty-six thousand, five hundred seventy".