20145931 has 8 divisors (see below), whose sum is σ = 21749504. Its totient is φ = 18550080.

The previous prime is 20145911. The next prime is 20145943. The reversal of 20145931 is 13954102.

20145931 = T₁₇₅₄ + T₁₇₅₅ + ... + T₁₇₆₆.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20145931 - 2⁵ = 20145899 is a prime.

It is a super-2 number, since 2×20145931² = 811717071713522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20145896 and 20145905.

It is not an unprimeable number, because it can be changed into a prime (20145911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4246 + ... + 7636.

It is an arithmetic number, because the mean of its divisors is an integer number (2718688).

Almost surely, 2^20145931 is an apocalyptic number.

20145931 is a deficient number, since it is larger than the sum of its proper divisors (1603573).

20145931 is a wasteful number, since it uses less digits than its factorization.

20145931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3861.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 20145931 is about 4488.4218830230. The cubic root of 20145931 is about 272.1003585477.

The spelling of 20145931 in words is "twenty million, one hundred forty-five thousand, nine hundred thirty-one".