81703890 has 48 divisors (see below), whose sum is σ = 220304448. Its totient is φ = 21787056.

The previous prime is 81703871. The next prime is 81703931. The reversal of 81703890 is 9830718.

It is a super-2 number, since 2×81703890² = 13351051282264200, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14382 + ... + 19241.

It is an arithmetic number, because the mean of its divisors is an integer number (4589676).

Almost surely, 2^81703890 is an apocalyptic number.

81703890 is an abundant number, since it is smaller than the sum of its proper divisors (138600558).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81703890 is a wasteful number, since it uses less digits than its factorization.

81703890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33645 (or 33633 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 81703890 is about 9039.0204115269. The cubic root of 81703890 is about 433.9245729594.

The spelling of 81703890 in words is "eighty-one million, seven hundred three thousand, eight hundred ninety".