2145216406 has 4 divisors (see below), whose sum is σ = 3217824612. Its totient is φ = 1072608202.

The previous prime is 2145216397. The next prime is 2145216407. The reversal of 2145216406 is 6046125412.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2145216407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 536304100 + ... + 536304103.

It is an arithmetic number, because the mean of its divisors is an integer number (804456153).

Almost surely, 2^2145216406 is an apocalyptic number.

2145216406 is a deficient number, since it is larger than the sum of its proper divisors (1072608206).

2145216406 is a wasteful number, since it uses less digits than its factorization.

2145216406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1072608205.

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 2145216406 is about 46316.4809328170. The cubic root of 2145216406 is about 1289.7049594669.

The spelling of 2145216406 in words is "two billion, one hundred forty-five million, two hundred sixteen thousand, four hundred six".