81251270 has 8 divisors (see below), whose sum is σ = 146252304. Its totient is φ = 32500504.

The previous prime is 81251267. The next prime is 81251293. The reversal of 81251270 is 7215218.

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

It is a super-2 number, since 2×81251270² = 13203537753225800, which contains 22 as substring.

It is a congruent number.

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, 4062554 + ... + 4062573.

It is an arithmetic number, because the mean of its divisors is an integer number (18281538).

Almost surely, 2^81251270 is an apocalyptic number.

81251270 is a deficient number, since it is larger than the sum of its proper divisors (65001034).

81251270 is a wasteful number, since it uses less digits than its factorization.

81251270 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8125134.

The product of its (nonzero) digits is 1120, while the sum is 26.

The square root of 81251270 is about 9013.9486353096. The cubic root of 81251270 is about 433.1218093226.

Adding to 81251270 its reverse (7215218), we get a palindrome (88466488).

The spelling of 81251270 in words is "eighty-one million, two hundred fifty-one thousand, two hundred seventy".