15722989 has 2 divisors, whose sum is σ = 15722990. Its totient is φ = 15722988.

The previous prime is 15722963. The next prime is 15722999. The reversal of 15722989 is 98922751.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15721225 + 1764 = 3965^2 + 42^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15722989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15722999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7861494 + 7861495.

It is an arithmetic number, because the mean of its divisors is an integer number (7861495).

Almost surely, 2^15722989 is an apocalyptic number.

It is an amenable number.

15722989 is a deficient number, since it is larger than the sum of its proper divisors (1).

15722989 is an equidigital number, since it uses as much as digits as its factorization.

15722989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 43.

The square root of 15722989 is about 3965.2224401665. Note that the first 3 decimals coincide. The cubic root of 15722989 is about 250.5215193139.

The spelling of 15722989 in words is "fifteen million, seven hundred twenty-two thousand, nine hundred eighty-nine".