81515029 has 4 divisors (see below), whose sum is σ = 82663200. Its totient is φ = 80366860.

The previous prime is 81514999. The next prime is 81515041. The reversal of 81515029 is 92051518.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81515029 - 2¹³ = 81506837 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81515129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 573979 + ... + 574120.

It is an arithmetic number, because the mean of its divisors is an integer number (20665800).

Almost surely, 2^81515029 is an apocalyptic number.

It is an amenable number.

81515029 is a deficient number, since it is larger than the sum of its proper divisors (1148171).

81515029 is a wasteful number, since it uses less digits than its factorization.

81515029 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1148170.

The product of its (nonzero) digits is 3600, while the sum is 31.

The square root of 81515029 is about 9028.5673835886. The cubic root of 81515029 is about 433.5899717779.

The spelling of 81515029 in words is "eighty-one million, five hundred fifteen thousand, twenty-nine".