20391722 has 16 divisors (see below), whose sum is σ = 33197472. Its totient is φ = 9338160.

The previous prime is 20391713. The next prime is 20391737. The reversal of 20391722 is 22719302.

It is a super-2 number, since 2×20391722² = 831644652250568, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a junction number, because it is equal to n+sod(n) for n = 20391691 and 20391700.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 413 + ... + 6399.

It is an arithmetic number, because the mean of its divisors is an integer number (2074842).

Almost surely, 2^20391722 is an apocalyptic number.

20391722 is a deficient number, since it is larger than the sum of its proper divisors (12805750).

20391722 is a wasteful number, since it uses less digits than its factorization.

20391722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6133.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 20391722 is about 4515.7194332686. The cubic root of 20391722 is about 273.2024778495.

The spelling of 20391722 in words is "twenty million, three hundred ninety-one thousand, seven hundred twenty-two".