20727421 has 12 divisors (see below), whose sum is σ = 24537436. Its totient is φ = 17392320.

The previous prime is 20727409. The next prime is 20727433. The reversal of 20727421 is 12472702.

It is an interprime number because it is at equal distance from previous prime (20727409) and next prime (20727433).

It can be written as a sum of positive squares in 2 ways, for example, as 7868025 + 12859396 = 2805^2 + 3586^2 .

It is not a de Polignac number, because 20727421 - 2¹¹ = 20725373 is a prime.

It is a super-2 number, since 2×20727421² = 859251962622482, which contains 22 as substring.

It is a hoax number, since the sum of its digits (25) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20727451) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5016 + ... + 8161.

Almost surely, 2^20727421 is an apocalyptic number.

It is an amenable number.

20727421 is a deficient number, since it is larger than the sum of its proper divisors (3810015).

20727421 is a wasteful number, since it uses less digits than its factorization.

20727421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13212 (or 13201 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 25.

The square root of 20727421 is about 4552.7377477733. The cubic root of 20727421 is about 274.6935252416.

The spelling of 20727421 in words is "twenty million, seven hundred twenty-seven thousand, four hundred twenty-one".