81029290 has 8 divisors (see below), whose sum is σ = 145852740. Its totient is φ = 32411712.

The previous prime is 81029287. The next prime is 81029309. The reversal of 81029290 is 9292018.

It can be written as a sum of positive squares in 2 ways, for example, as 78623689 + 2405601 = 8867^2 + 1551^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4051455 + ... + 4051474.

Almost surely, 2^81029290 is an apocalyptic number.

81029290 is a deficient number, since it is larger than the sum of its proper divisors (64823450).

81029290 is a wasteful number, since it uses less digits than its factorization.

81029290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8102936.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 81029290 is about 9001.6270751459. The cubic root of 81029290 is about 432.7270172640.

The spelling of 81029290 in words is "eighty-one million, twenty-nine thousand, two hundred ninety".