21140420402 has 4 divisors (see below), whose sum is σ = 31710630606. Its totient is φ = 10570210200.

The previous prime is 21140420351. The next prime is 21140420417. The reversal of 21140420402 is 20402404112.

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

It can be written as a sum of positive squares in only one way, i.e., 17197961881 + 3942458521 = 131141^2 + 62789^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5285105099 + ... + 5285105102.

Almost surely, 2^21140420402 is an apocalyptic number.

21140420402 is a deficient number, since it is larger than the sum of its proper divisors (10570210204).

21140420402 is a wasteful number, since it uses less digits than its factorization.

21140420402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10570210203.

The product of its (nonzero) digits is 512, while the sum is 20.

Adding to 21140420402 its reverse (20402404112), we get a palindrome (41542824514).

The spelling of 21140420402 in words is "twenty-one billion, one hundred forty million, four hundred twenty thousand, four hundred two".