20735731 has 2 divisors, whose sum is σ = 20735732. Its totient is φ = 20735730.

The previous prime is 20735713. The next prime is 20735747. The reversal of 20735731 is 13753702.

Together with previous prime (20735713) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20735731 - 2²³ = 12347123 is a prime.

It is a super-2 number, since 2×20735731² = 859941080208722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20735731.

It is not a weakly prime, because it can be changed into another prime (20735711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10367865 + 10367866.

It is an arithmetic number, because the mean of its divisors is an integer number (10367866).

Almost surely, 2^20735731 is an apocalyptic number.

20735731 is a deficient number, since it is larger than the sum of its proper divisors (1).

20735731 is an equidigital number, since it uses as much as digits as its factorization.

20735731 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4410, while the sum is 28.

The square root of 20735731 is about 4553.6502939949. The cubic root of 20735731 is about 274.7302302133.

The spelling of 20735731 in words is "twenty million, seven hundred thirty-five thousand, seven hundred thirty-one".