81563630 has 16 divisors (see below), whose sum is σ = 148827024. Its totient is φ = 32178240.

The previous prime is 81563627. The next prime is 81563633. The reversal of 81563630 is 3636518.

It is an interprime number because it is at equal distance from previous prime (81563627) and next prime (81563633).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81563633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55136 + ... + 56595.

It is an arithmetic number, because the mean of its divisors is an integer number (9301689).

Almost surely, 2^81563630 is an apocalyptic number.

81563630 is a deficient number, since it is larger than the sum of its proper divisors (67263394).

81563630 is a wasteful number, since it uses less digits than its factorization.

81563630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111811.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 81563630 is about 9031.2584948057. The cubic root of 81563630 is about 433.6761265227.

The spelling of 81563630 in words is "eighty-one million, five hundred sixty-three thousand, six hundred thirty".