81640295 has 8 divisors (see below), whose sum is σ = 106874640. Its totient is φ = 59374720.

The previous prime is 81640291. The next prime is 81640303. The reversal of 81640295 is 59204618.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81640295 - 2² = 81640291 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81640291) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 742130 + ... + 742239.

It is an arithmetic number, because the mean of its divisors is an integer number (13359330).

Almost surely, 2^81640295 is an apocalyptic number.

81640295 is a deficient number, since it is larger than the sum of its proper divisors (25234345).

81640295 is a wasteful number, since it uses less digits than its factorization.

81640295 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1484385.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 81640295 is about 9035.5019229703. The cubic root of 81640295 is about 433.8119606304.

The spelling of 81640295 in words is "eighty-one million, six hundred forty thousand, two hundred ninety-five".