20729631 has 16 divisors (see below), whose sum is σ = 29926400. Its totient is φ = 12687840.

The previous prime is 20729629. The next prime is 20729633. The reversal of 20729631 is 13692702.

It is an interprime number because it is at equal distance from previous prime (20729629) and next prime (20729633).

It is not a de Polignac number, because 20729631 - 2¹ = 20729629 is a prime.

It is a super-2 number, since 2×20729631² = 859435202792322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20729633) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6426 + ... + 9096.

It is an arithmetic number, because the mean of its divisors is an integer number (1870400).

Almost surely, 2^20729631 is an apocalyptic number.

20729631 is a deficient number, since it is larger than the sum of its proper divisors (9196769).

20729631 is a wasteful number, since it uses less digits than its factorization.

20729631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2886.

The product of its (nonzero) digits is 4536, while the sum is 30.

The square root of 20729631 is about 4552.9804524070. The cubic root of 20729631 is about 274.7032876897.

The spelling of 20729631 in words is "twenty million, seven hundred twenty-nine thousand, six hundred thirty-one".