20291678531 has 2 divisors, whose sum is σ = 20291678532. Its totient is φ = 20291678530.

The previous prime is 20291678521. The next prime is 20291678557. The reversal of 20291678531 is 13587619202.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20291678531 - 2¹⁰ = 20291677507 is a prime.

It is a super-2 number, since 2×20291678531² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (20291678521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10145839265 + 10145839266.

It is an arithmetic number, because the mean of its divisors is an integer number (10145839266).

Almost surely, 2^20291678531 is an apocalyptic number.

20291678531 is a deficient number, since it is larger than the sum of its proper divisors (1).

20291678531 is an equidigital number, since it uses as much as digits as its factorization.

20291678531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 181440, while the sum is 44.

The spelling of 20291678531 in words is "twenty billion, two hundred ninety-one million, six hundred seventy-eight thousand, five hundred thirty-one".