81303806949 has 4 divisors (see below), whose sum is σ = 108405075936. Its totient is φ = 54202537964.

The previous prime is 81303806939. The next prime is 81303806957. The reversal of 81303806949 is 94960830318.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81303806949 - 2⁵ = 81303806917 is a prime.

It is a super-2 number, since 2×81303806949² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81303806939) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13550634489 + ... + 13550634494.

It is an arithmetic number, because the mean of its divisors is an integer number (27101268984).

Almost surely, 2^81303806949 is an apocalyptic number.

It is an amenable number.

81303806949 is a deficient number, since it is larger than the sum of its proper divisors (27101268987).

81303806949 is a wasteful number, since it uses less digits than its factorization.

81303806949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27101268986.

The product of its (nonzero) digits is 1119744, while the sum is 51.

The spelling of 81303806949 in words is "eighty-one billion, three hundred three million, eight hundred six thousand, nine hundred forty-nine".