20451216 has 40 divisors (see below), whose sum is σ = 53835840. Its totient is φ = 6687616.

The previous prime is 20451203. The next prime is 20451241. The reversal of 20451216 is 61215402.

It is a junction number, because it is equal to n+sod(n) for n = 20451192 and 20451201.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1476 + ... + 6563.

It is an arithmetic number, because the mean of its divisors is an integer number (1345896).

Almost surely, 2^20451216 is an apocalyptic number.

It is an amenable number.

20451216 is an abundant number, since it is smaller than the sum of its proper divisors (33384624).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20451216 is a wasteful number, since it uses less digits than its factorization.

20451216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8103 (or 8097 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 20451216 is about 4522.3020686372. The cubic root of 20451216 is about 273.4679144248.

Adding to 20451216 its reverse (61215402), we get a palindrome (81666618).

The spelling of 20451216 in words is "twenty million, four hundred fifty-one thousand, two hundred sixteen".