81145402 has 8 divisors (see below), whose sum is σ = 131081076. Its totient is φ = 37451712.

The previous prime is 81145399. The next prime is 81145411. The reversal of 81145402 is 20454118.

It can be written as a sum of positive squares in 2 ways, for example, as 80263681 + 881721 = 8959^2 + 939^2 .

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, 1560463 + ... + 1560514.

Almost surely, 2^81145402 is an apocalyptic number.

81145402 is a deficient number, since it is larger than the sum of its proper divisors (49935674).

81145402 is a wasteful number, since it uses less digits than its factorization.

81145402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3120992.

The product of its (nonzero) digits is 1280, while the sum is 25.

The square root of 81145402 is about 9008.0742670118. The cubic root of 81145402 is about 432.9336125946.

The spelling of 81145402 in words is "eighty-one million, one hundred forty-five thousand, four hundred two".