20666601501 has 32 divisors (see below), whose sum is σ = 33941553408. Its totient is φ = 10892344320.

The previous prime is 20666601443. The next prime is 20666601533. The reversal of 20666601501 is 10510666602.

It is not a de Polignac number, because 20666601501 - 2⁹ = 20666600989 is a prime.

It is a super-2 number, since 2×20666601501² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20666601581) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 318981 + ... + 378261.

It is an arithmetic number, because the mean of its divisors is an integer number (1060673544).

Almost surely, 2^20666601501 is an apocalyptic number.

20666601501 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20666601501 is a deficient number, since it is larger than the sum of its proper divisors (13274951907).

20666601501 is a wasteful number, since it uses less digits than its factorization.

20666601501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60581.

The product of its (nonzero) digits is 12960, while the sum is 33.

The spelling of 20666601501 in words is "twenty billion, six hundred sixty-six million, six hundred one thousand, five hundred one".