20837121 has 16 divisors (see below), whose sum is σ = 30046464. Its totient is φ = 12794624.

The previous prime is 20837111. The next prime is 20837123. The reversal of 20837121 is 12173802.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20837121 is a prime.

It is a super-2 number, since 2×20837121² = 868371223137282, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20837091 and 20837100.

It is not an unprimeable number, because it can be changed into a prime (20837123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1950 + ... + 6743.

It is an arithmetic number, because the mean of its divisors is an integer number (1877904).

Almost surely, 2^20837121 is an apocalyptic number.

It is an amenable number.

20837121 is a deficient number, since it is larger than the sum of its proper divisors (9209343).

20837121 is a wasteful number, since it uses less digits than its factorization.

20837121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8760.

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 20837121 is about 4564.7695451140. The cubic root of 20837121 is about 275.1772785304.

The spelling of 20837121 in words is "twenty million, eight hundred thirty-seven thousand, one hundred twenty-one".