20154031643 has 4 divisors (see below), whose sum is σ = 20804161728. Its totient is φ = 19503901560.

The previous prime is 20154031561. The next prime is 20154031691. The reversal of 20154031643 is 34613045102.

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

It is a cyclic number.

It is not a de Polignac number, because 20154031643 - 2¹⁸ = 20153769499 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20154037643) 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, 325064996 + ... + 325065057.

It is an arithmetic number, because the mean of its divisors is an integer number (5201040432).

Almost surely, 2^20154031643 is an apocalyptic number.

20154031643 is a deficient number, since it is larger than the sum of its proper divisors (650130085).

20154031643 is an equidigital number, since it uses as much as digits as its factorization.

20154031643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 650130084.

The product of its (nonzero) digits is 8640, while the sum is 29.

Adding to 20154031643 its reverse (34613045102), we get a palindrome (54767076745).

The spelling of 20154031643 in words is "twenty billion, one hundred fifty-four million, thirty-one thousand, six hundred forty-three".