81949004 has 6 divisors (see below), whose sum is σ = 143410764. Its totient is φ = 40974500.

The previous prime is 81949001. The next prime is 81949009. The reversal of 81949004 is 40094918.

It is not an unprimeable number, because it can be changed into a prime (81949001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10243622 + ... + 10243629.

It is an arithmetic number, because the mean of its divisors is an integer number (23901794).

Almost surely, 2^81949004 is an apocalyptic number.

It is an amenable number.

81949004 is a deficient number, since it is larger than the sum of its proper divisors (61461760).

81949004 is a wasteful number, since it uses less digits than its factorization.

81949004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20487255 (or 20487253 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 81949004 is about 9052.5689171638. The cubic root of 81949004 is about 434.3580684462.

The spelling of 81949004 in words is "eighty-one million, nine hundred forty-nine thousand, four".