20951406 has 64 divisors (see below), whose sum is σ = 54489600. Its totient is φ = 5842368.

The previous prime is 20951387. The next prime is 20951407. The reversal of 20951406 is 60415902.

20951406 is a `hidden beast` number, since 209 + 51 + 406 = 666.

It is a super-2 number, since 2×20951406² = 877922826753672, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20951406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20951407) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15610 + ... + 16898.

It is an arithmetic number, because the mean of its divisors is an integer number (851400).

Almost surely, 2^20951406 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20951406, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27244800).

20951406 is an abundant number, since it is smaller than the sum of its proper divisors (33538194).

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

20951406 is a wasteful number, since it uses less digits than its factorization.

20951406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1350 (or 1344 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 20951406 is about 4577.2705840927. The cubic root of 20951406 is about 275.6794482650.

It can be divided in two parts, 209 and 51406, that added together give a palindrome (51615).

The spelling of 20951406 in words is "twenty million, nine hundred fifty-one thousand, four hundred six".