81902104 has 8 divisors (see below), whose sum is σ = 153566460. Its totient is φ = 40951048.

The previous prime is 81902099. The next prime is 81902129. The reversal of 81902104 is 40120918.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5118874 + ... + 5118889.

Almost surely, 2^81902104 is an apocalyptic number.

It is an amenable number.

81902104 is a deficient number, since it is larger than the sum of its proper divisors (71664356).

81902104 is a wasteful number, since it uses less digits than its factorization.

81902104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10237769 (or 10237765 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 81902104 is about 9049.9781215205. The cubic root of 81902104 is about 434.2751905592.

The spelling of 81902104 in words is "eighty-one million, nine hundred two thousand, one hundred four".