81287630 has 16 divisors (see below), whose sum is σ = 149721264. Its totient is φ = 31758720.

The previous prime is 81287593. The next prime is 81287641. The reversal of 81287630 is 3678218.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 94091 + ... + 94950.

It is an arithmetic number, because the mean of its divisors is an integer number (9357579).

Almost surely, 2^81287630 is an apocalyptic number.

81287630 is a deficient number, since it is larger than the sum of its proper divisors (68433634).

81287630 is a wasteful number, since it uses less digits than its factorization.

81287630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189091.

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

The square root of 81287630 is about 9015.9652838728. The cubic root of 81287630 is about 433.1864071250.

The spelling of 81287630 in words is "eighty-one million, two hundred eighty-seven thousand, six hundred thirty".