215421402 has 16 divisors (see below), whose sum is σ = 492391872. Its totient is φ = 61548960.

The previous prime is 215421379. The next prime is 215421407. The reversal of 215421402 is 204124512.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (215421407) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2564499 + ... + 2564582.

It is an arithmetic number, because the mean of its divisors is an integer number (30774492).

Almost surely, 2^215421402 is an apocalyptic number.

215421402 is an abundant number, since it is smaller than the sum of its proper divisors (276970470).

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

215421402 is a wasteful number, since it uses less digits than its factorization.

215421402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5129093.

The product of its (nonzero) digits is 640, while the sum is 21.

The square root of 215421402 is about 14677.2409532582. The cubic root of 215421402 is about 599.4637820377.

Adding to 215421402 its reverse (204124512), we get a palindrome (419545914).

The spelling of 215421402 in words is "two hundred fifteen million, four hundred twenty-one thousand, four hundred two".