20521701 has 8 divisors (see below), whose sum is σ = 30402560. Its totient is φ = 13681116.

The previous prime is 20521679. The next prime is 20521723. The reversal of 20521701 is 10712502.

It is an interprime number because it is at equal distance from previous prime (20521679) and next prime (20521723).

It is not a de Polignac number, because 20521701 - 2⁷ = 20521573 is a prime.

It is a super-2 number, since 2×20521701² = 842280423866802, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20521001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 380005 + ... + 380058.

It is an arithmetic number, because the mean of its divisors is an integer number (3800320).

Almost surely, 2^20521701 is an apocalyptic number.

It is an amenable number.

20521701 is a deficient number, since it is larger than the sum of its proper divisors (9880859).

20521701 is an equidigital number, since it uses as much as digits as its factorization.

20521701 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 760072 (or 760066 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 18.

The square root of 20521701 is about 4530.0884097333. The cubic root of 20521701 is about 273.7817227265.

The spelling of 20521701 in words is "twenty million, five hundred twenty-one thousand, seven hundred one".