81667337954 has 4 divisors (see below), whose sum is σ = 122501006934. Its totient is φ = 40833668976.

The previous prime is 81667337953. The next prime is 81667338001. The reversal of 81667337954 is 45973376618.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 48424203025 + 33243134929 = 220055^2 + 182327^2 .

It is a super-2 number, since 2×81667337954² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81667337893 and 81667337902.

It is not an unprimeable number, because it can be changed into a prime (81667337953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20416834487 + ... + 20416834490.

Almost surely, 2^81667337954 is an apocalyptic number.

81667337954 is a deficient number, since it is larger than the sum of its proper divisors (40833668980).

81667337954 is a wasteful number, since it uses less digits than its factorization.

81667337954 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40833668979.

The product of its digits is 22861440, while the sum is 59.

The spelling of 81667337954 in words is "eighty-one billion, six hundred sixty-seven million, three hundred thirty-seven thousand, nine hundred fifty-four".