81615001 has 12 divisors (see below), whose sum is σ = 88703760. Its totient is φ = 75057840.

The previous prime is 81614987. The next prime is 81615031. The reversal of 81615001 is 10051618.

It is not a de Polignac number, because 81615001 - 2¹³ = 81606809 is a prime.

It is a super-2 number, since 2×81615001² = 13322016776460002, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81615031) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 55210 + ... + 56668.

It is an arithmetic number, because the mean of its divisors is an integer number (7391980).

Almost surely, 2^81615001 is an apocalyptic number.

It is an amenable number.

81615001 is a deficient number, since it is larger than the sum of its proper divisors (7088759).

81615001 is a wasteful number, since it uses less digits than its factorization.

81615001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1816 (or 1803 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 22.

The square root of 81615001 is about 9034.1021136580. The cubic root of 81615001 is about 433.7671544345.

Adding to 81615001 its reverse (10051618), we get a palindrome (91666619).

The spelling of 81615001 in words is "eighty-one million, six hundred fifteen thousand, one".