20440430987 has 2 divisors, whose sum is σ = 20440430988. Its totient is φ = 20440430986.

The previous prime is 20440430957. The next prime is 20440431041. The reversal of 20440430987 is 78903404402.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20440430987 is a prime.

It is a super-2 number, since 2×20440430987² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20440430957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10220215493 + 10220215494.

It is an arithmetic number, because the mean of its divisors is an integer number (10220215494).

Almost surely, 2^20440430987 is an apocalyptic number.

20440430987 is a deficient number, since it is larger than the sum of its proper divisors (1).

20440430987 is an equidigital number, since it uses as much as digits as its factorization.

20440430987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 193536, while the sum is 41.

The spelling of 20440430987 in words is "twenty billion, four hundred forty million, four hundred thirty thousand, nine hundred eighty-seven".