20981415 has 64 divisors (see below), whose sum is σ = 43545600. Its totient is φ = 8377344.

The previous prime is 20981407. The next prime is 20981447. The reversal of 20981415 is 51418902.

It is a happy number.

It is not a de Polignac number, because 20981415 - 2³ = 20981407 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 25531 + ... + 26339.

It is an arithmetic number, because the mean of its divisors is an integer number (680400).

Almost surely, 2^20981415 is an apocalyptic number.

20981415 is an abundant number, since it is smaller than the sum of its proper divisors (22564185).

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

20981415 is a wasteful number, since it uses less digits than its factorization.

20981415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 856.

The product of its (nonzero) digits is 2880, while the sum is 30.

The square root of 20981415 is about 4580.5474563637. The cubic root of 20981415 is about 275.8110053536.

The spelling of 20981415 in words is "twenty million, nine hundred eighty-one thousand, four hundred fifteen".