20212121015 has 12 divisors (see below), whose sum is σ = 25765210776. Its totient is φ = 15218537088.

The previous prime is 20212121009. The next prime is 20212121021. The reversal of 20212121015 is 51012121202.

It is an interprime number because it is at equal distance from previous prime (20212121009) and next prime (20212121021).

It is not a de Polignac number, because 20212121015 - 2⁸ = 20212120759 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20212120984 and 20212121002.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6992369 + ... + 6995258.

It is an arithmetic number, because the mean of its divisors is an integer number (2147100898).

Almost surely, 2^20212121015 is an apocalyptic number.

20212121015 is a deficient number, since it is larger than the sum of its proper divisors (5553089761).

20212121015 is a wasteful number, since it uses less digits than its factorization.

20212121015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13987666 (or 13987649 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 17.

Adding to 20212121015 its reverse (51012121202), we get a palindrome (71224242217).

The spelling of 20212121015 in words is "twenty billion, two hundred twelve million, one hundred twenty-one thousand, fifteen".