19997402 has 4 divisors (see below), whose sum is σ = 29996106. Its totient is φ = 9998700.

The previous prime is 19997399. The next prime is 19997413. The reversal of 19997402 is 20479991.

It is a happy number.

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., 19704721 + 292681 = 4439^2 + 541^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 19997402.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4999349 + ... + 4999352.

Almost surely, 2^19997402 is an apocalyptic number.

19997402 is a deficient number, since it is larger than the sum of its proper divisors (9998704).

19997402 is an equidigital number, since it uses as much as digits as its factorization.

19997402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9998703.

The product of its (nonzero) digits is 40824, while the sum is 41.

The square root of 19997402 is about 4471.8454803358. The cubic root of 19997402 is about 271.4300077223.

The spelling of 19997402 in words is "nineteen million, nine hundred ninety-seven thousand, four hundred two".