81897896 has 8 divisors (see below), whose sum is σ = 153558570. Its totient is φ = 40948944.

The previous prime is 81897887. The next prime is 81897911. The reversal of 81897896 is 69879818.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 46922500 + 34975396 = 6850^2 + 5914^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5118611 + ... + 5118626.

Almost surely, 2^81897896 is an apocalyptic number.

It is an amenable number.

81897896 is a deficient number, since it is larger than the sum of its proper divisors (71660674).

81897896 is a wasteful number, since it uses less digits than its factorization.

81897896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10237243 (or 10237239 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 56.

The square root of 81897896 is about 9049.7456317844. The cubic root of 81897896 is about 434.2677529753.

The spelling of 81897896 in words is "eighty-one million, eight hundred ninety-seven thousand, eight hundred ninety-six".