21371402 has 24 divisors (see below), whose sum is σ = 35397324. Its totient is φ = 9669504.

The previous prime is 21371401. The next prime is 21371423. The reversal of 21371402 is 20417312.

It can be written as a sum of positive squares in 6 ways, for example, as 5202961 + 16168441 = 2281^2 + 4021^2 .

It is not an unprimeable number, because it can be changed into a prime (21371401) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17318 + ... + 18510.

Almost surely, 2^21371402 is an apocalyptic number.

21371402 is a deficient number, since it is larger than the sum of its proper divisors (14025922).

21371402 is a wasteful number, since it uses less digits than its factorization.

21371402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1274 (or 1261 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 21371402 is about 4622.9213707352. The cubic root of 21371402 is about 277.5093825792.

Adding to 21371402 its reverse (20417312), we get a palindrome (41788714).

The spelling of 21371402 in words is "twenty-one million, three hundred seventy-one thousand, four hundred two".