81962020858 has 4 divisors (see below), whose sum is σ = 122943031290. Its totient is φ = 40981010428.

The previous prime is 81962020853. The next prime is 81962020859. The reversal of 81962020858 is 85802026918.

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

It can be written as a sum of positive squares in only one way, i.e., 72477793089 + 9484227769 = 269217^2 + 97387^2 .

It is not an unprimeable number, because it can be changed into a prime (81962020853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20490505213 + ... + 20490505216.

Almost surely, 2^81962020858 is an apocalyptic number.

81962020858 is a deficient number, since it is larger than the sum of its proper divisors (40981010432).

81962020858 is a wasteful number, since it uses less digits than its factorization.

81962020858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40981010431.

The product of its (nonzero) digits is 552960, while the sum is 49.

The spelling of 81962020858 in words is "eighty-one billion, nine hundred sixty-two million, twenty thousand, eight hundred fifty-eight".