20951280 has 120 divisors (see below), whose sum is σ = 80432352. Its totient is φ = 4787712.

The previous prime is 20951279. The next prime is 20951291. The reversal of 20951280 is 8215902.

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×20951280² = 877912267276800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2962 + ... + 7118.

Almost surely, 2^20951280 is an apocalyptic number.

20951280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20951280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40216176).

20951280 is an abundant number, since it is smaller than the sum of its proper divisors (59481072).

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

20951280 is a wasteful number, since it uses less digits than its factorization.

20951280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4183 (or 4174 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 20951280 is about 4577.2568204111. The cubic root of 20951280 is about 275.6788956262.

It can be divided in two parts, 2095 and 1280, that added together give a cube (3375 = 15³).

The spelling of 20951280 in words is "twenty million, nine hundred fifty-one thousand, two hundred eighty".