81749652 has 12 divisors (see below), whose sum is σ = 190749216. Its totient is φ = 27249880.

The previous prime is 81749641. The next prime is 81749663. The reversal of 81749652 is 25694718.

It is an interprime number because it is at equal distance from previous prime (81749641) and next prime (81749663).

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×81749652² = 13366011204242208, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3406224 + ... + 3406247.

It is an arithmetic number, because the mean of its divisors is an integer number (15895768).

Almost surely, 2^81749652 is an apocalyptic number.

It is an amenable number.

81749652 is an abundant number, since it is smaller than the sum of its proper divisors (108999564).

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

81749652 is a wasteful number, since it uses less digits than its factorization.

81749652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6812478 (or 6812476 counting only the distinct ones).

The product of its digits is 120960, while the sum is 42.

The square root of 81749652 is about 9041.5514155481. The cubic root of 81749652 is about 434.0055709394.

The spelling of 81749652 in words is "eighty-one million, seven hundred forty-nine thousand, six hundred fifty-two".