81630901 has 16 divisors (see below), whose sum is σ = 91127808. Its totient is φ = 72500400.

The previous prime is 81630881. The next prime is 81630919. The reversal of 81630901 is 10903618.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 81630901 - 2²¹ = 79533749 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81630901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81630961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 98776 + ... + 99598.

It is an arithmetic number, because the mean of its divisors is an integer number (5695488).

Almost surely, 2^81630901 is an apocalyptic number.

It is an amenable number.

81630901 is a deficient number, since it is larger than the sum of its proper divisors (9496907).

81630901 is a wasteful number, since it uses less digits than its factorization.

81630901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1032.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 81630901 is about 9034.9820697110. The cubic root of 81630901 is about 433.7953210291.

The spelling of 81630901 in words is "eighty-one million, six hundred thirty thousand, nine hundred one".