20783720121 has 8 divisors (see below), whose sum is σ = 27720323904. Its totient is φ = 13851464880.

The previous prime is 20783720119. The next prime is 20783720143. The reversal of 20783720121 is 12102738702.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20783720121 - 2¹ = 20783720119 is a prime.

It is a super-3 number, since 3×20783720121³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (20783720101) 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, 1075966 + ... + 1095111.

It is an arithmetic number, because the mean of its divisors is an integer number (3465040488).

Almost surely, 2^20783720121 is an apocalyptic number.

It is an amenable number.

20783720121 is a deficient number, since it is larger than the sum of its proper divisors (6936603783).

20783720121 is a wasteful number, since it uses less digits than its factorization.

20783720121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2174271.

The product of its (nonzero) digits is 9408, while the sum is 33.

The spelling of 20783720121 in words is "twenty billion, seven hundred eighty-three million, seven hundred twenty thousand, one hundred twenty-one".