81247616 has 16 divisors (see below), whose sum is σ = 161860740. Its totient is φ = 40623744.

The previous prime is 81247583. The next prime is 81247627. The reversal of 81247616 is 61674218.

It is a tau number, because it is divible by the number of its divisors (16).

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, 317246 + ... + 317501.

Almost surely, 2^81247616 is an apocalyptic number.

It is an amenable number.

81247616 is a deficient number, since it is larger than the sum of its proper divisors (80613124).

81247616 is an equidigital number, since it uses as much as digits as its factorization.

81247616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 634761 (or 634749 counting only the distinct ones).

The product of its digits is 16128, while the sum is 35.

The square root of 81247616 is about 9013.7459471631. The cubic root of 81247616 is about 433.1153164977.

The spelling of 81247616 in words is "eighty-one million, two hundred forty-seven thousand, six hundred sixteen".