21961402 has 4 divisors (see below), whose sum is σ = 32942106. Its totient is φ = 10980700.

The previous prime is 21961369. The next prime is 21961417. The reversal of 21961402 is 20416912.

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., 12895281 + 9066121 = 3591^2 + 3011^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5490349 + ... + 5490352.

Almost surely, 2^21961402 is an apocalyptic number.

21961402 is a deficient number, since it is larger than the sum of its proper divisors (10980704).

21961402 is a wasteful number, since it uses less digits than its factorization.

21961402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10980703.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 21961402 is about 4686.2993929112. The cubic root of 21961402 is about 280.0399687842.

The spelling of 21961402 in words is "twenty-one million, nine hundred sixty-one thousand, four hundred two".