81469477487 has 4 divisors (see below), whose sum is σ = 81470914800. Its totient is φ = 81468040176.

The previous prime is 81469477423. The next prime is 81469477493. The reversal of 81469477487 is 78477496418.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81469477487 - 2⁶ = 81469477423 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81469470487) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 629987 + ... + 748212.

It is an arithmetic number, because the mean of its divisors is an integer number (20367728700).

Almost surely, 2^81469477487 is an apocalyptic number.

81469477487 is a deficient number, since it is larger than the sum of its proper divisors (1437313).

81469477487 is a wasteful number, since it uses less digits than its factorization.

81469477487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1437312.

The product of its digits is 75866112, while the sum is 65.

The spelling of 81469477487 in words is "eighty-one billion, four hundred sixty-nine million, four hundred seventy-seven thousand, four hundred eighty-seven".