20937551 has 2 divisors, whose sum is σ = 20937552. Its totient is φ = 20937550.

The previous prime is 20937529. The next prime is 20937559. The reversal of 20937551 is 15573902.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20937551 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20937559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10468775 + 10468776.

It is an arithmetic number, because the mean of its divisors is an integer number (10468776).

Almost surely, 2^20937551 is an apocalyptic number.

20937551 is a deficient number, since it is larger than the sum of its proper divisors (1).

20937551 is an equidigital number, since it uses as much as digits as its factorization.

20937551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9450, while the sum is 32.

The square root of 20937551 is about 4575.7568772827. The cubic root of 20937551 is about 275.6186666480.

The spelling of 20937551 in words is "twenty million, nine hundred thirty-seven thousand, five hundred fifty-one".