7816121854 has 4 divisors (see below), whose sum is σ = 11724182784. Its totient is φ = 3908060926.

The previous prime is 7816121843. The next prime is 7816121857. The reversal of 7816121854 is 4581216187.

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

It is a super-2 number, since 2×7816121854² (a number of 21 digits) contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a self number, because there is not a number n which added to its sum of digits gives 7816121854.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7816121857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1954030462 + ... + 1954030465.

It is an arithmetic number, because the mean of its divisors is an integer number (2931045696).

Almost surely, 2^7816121854 is an apocalyptic number.

7816121854 is a deficient number, since it is larger than the sum of its proper divisors (3908060930).

7816121854 is a wasteful number, since it uses less digits than its factorization.

7816121854 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3908060929.

The product of its digits is 107520, while the sum is 43.

The square root of 7816121854 is about 88408.8335744794. The cubic root of 7816121854 is about 1984.5578987800.

The spelling of 7816121854 in words is "seven billion, eight hundred sixteen million, one hundred twenty-one thousand, eight hundred fifty-four".