20291913 has 6 divisors (see below), whose sum is σ = 29310554. Its totient is φ = 13527936.

The previous prime is 20291903. The next prime is 20291969. The reversal of 20291913 is 31919202.

It can be written as a sum of positive squares in only one way, i.e., 20142144 + 149769 = 4488^2 + 387^2 .

It is not a de Polignac number, because 20291913 - 2¹⁰ = 20290889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20291903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1127320 + ... + 1127337.

Almost surely, 2^20291913 is an apocalyptic number.

It is an amenable number.

20291913 is a deficient number, since it is larger than the sum of its proper divisors (9018641).

20291913 is a wasteful number, since it uses less digits than its factorization.

20291913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2254663 (or 2254660 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 20291913 is about 4504.6545927518. The cubic root of 20291913 is about 272.7560111231.

The spelling of 20291913 in words is "twenty million, two hundred ninety-one thousand, nine hundred thirteen".