81900429 has 8 divisors (see below), whose sum is σ = 117600672. Its totient is φ = 50400240.

The previous prime is 81900409. The next prime is 81900439. The reversal of 81900429 is 92400918.

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

It is not a de Polignac number, because 81900429 - 2¹² = 81896333 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81900429.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81900409) 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, 1049967 + ... + 1050044.

It is an arithmetic number, because the mean of its divisors is an integer number (14700084).

Almost surely, 2^81900429 is an apocalyptic number.

It is an amenable number.

81900429 is a deficient number, since it is larger than the sum of its proper divisors (35700243).

81900429 is a wasteful number, since it uses less digits than its factorization.

81900429 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2100027.

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 81900429 is about 9049.8855793872. The cubic root of 81900429 is about 434.2722300496.

The spelling of 81900429 in words is "eighty-one million, nine hundred thousand, four hundred twenty-nine".