20421646601461 has 12 divisors (see below), whose sum is σ = 23756474472300. Its totient is φ = 17503766367360.

The previous prime is 20421646601401. The next prime is 20421646601467. The reversal of 20421646601461 is 16410664612402.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 13044420230436 + 7377226371025 = 3611706^2 + 2716105^2 .

It is not a de Polignac number, because 20421646601461 - 2¹⁷ = 20421646470389 is a prime.

It is a super-2 number, since 2×20421646601461² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20421646601467) 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, 4247386 + ... + 7673563.

It is an arithmetic number, because the mean of its divisors is an integer number (1979706206025).

Almost surely, 2^{20421646601461} is an apocalyptic number.

It is an amenable number.

20421646601461 is a deficient number, since it is larger than the sum of its proper divisors (3334827870839).

20421646601461 is a wasteful number, since it uses less digits than its factorization.

20421646601461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11955924 (or 11955917 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 43.

The spelling of 20421646601461 in words is "twenty trillion, four hundred twenty-one billion, six hundred forty-six million, six hundred one thousand, four hundred sixty-one".