81402645 has 8 divisors (see below), whose sum is σ = 130244256. Its totient is φ = 43414736.

The previous prime is 81402641. The next prime is 81402649. The reversal of 81402645 is 54620418.

It is an interprime number because it is at equal distance from previous prime (81402641) and next prime (81402649).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81402645 - 2² = 81402641 is a prime.

It is a super-2 number, since 2×81402645² = 13252781225992050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81402641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2713407 + ... + 2713436.

It is an arithmetic number, because the mean of its divisors is an integer number (16280532).

Almost surely, 2^81402645 is an apocalyptic number.

It is an amenable number.

81402645 is a deficient number, since it is larger than the sum of its proper divisors (48841611).

81402645 is a wasteful number, since it uses less digits than its factorization.

81402645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5426851.

The product of its (nonzero) digits is 7680, while the sum is 30.

The square root of 81402645 is about 9022.3414366782. The cubic root of 81402645 is about 433.3906180022.

The spelling of 81402645 in words is "eighty-one million, four hundred two thousand, six hundred forty-five".