81502207 has 4 divisors (see below), whose sum is σ = 81529000. Its totient is φ = 81475416.

The previous prime is 81502189. The next prime is 81502247. The reversal of 81502207 is 70220518.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81502207 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 (81502247) 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, 8148 + ... + 15145.

It is an arithmetic number, because the mean of its divisors is an integer number (20382250).

Almost surely, 2^81502207 is an apocalyptic number.

81502207 is a deficient number, since it is larger than the sum of its proper divisors (26793).

81502207 is a wasteful number, since it uses less digits than its factorization.

81502207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26792.

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 81502207 is about 9027.8572762312. The cubic root of 81502207 is about 433.5672365751.

The spelling of 81502207 in words is "eighty-one million, five hundred two thousand, two hundred seven".