20131954478 has 4 divisors (see below), whose sum is σ = 30197931720. Its totient is φ = 10065977238.

The previous prime is 20131954477. The next prime is 20131954481. The reversal of 20131954478 is 87445913102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87445913102 = 2 ⋅43722956551.

It is a super-2 number, since 2×20131954478² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20131954477) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5032988618 + ... + 5032988621.

It is an arithmetic number, because the mean of its divisors is an integer number (7549482930).

Almost surely, 2^20131954478 is an apocalyptic number.

20131954478 is a deficient number, since it is larger than the sum of its proper divisors (10065977242).

20131954478 is a wasteful number, since it uses less digits than its factorization.

20131954478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10065977241.

The product of its (nonzero) digits is 241920, while the sum is 44.

The spelling of 20131954478 in words is "twenty billion, one hundred thirty-one million, nine hundred fifty-four thousand, four hundred seventy-eight".