21400374 has 8 divisors (see below), whose sum is σ = 42800760. Its totient is φ = 7133456.

The previous prime is 21400367. The next prime is 21400381. The reversal of 21400374 is 47300412.

It is an interprime number because it is at equal distance from previous prime (21400367) and next prime (21400381).

It is a sphenic number, since it is the product of 3 distinct primes.

21400374 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 21400374.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1783359 + ... + 1783370.

It is an arithmetic number, because the mean of its divisors is an integer number (5350095).

Almost surely, 2^21400374 is an apocalyptic number.

21400374 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21400374 is a wasteful number, since it uses less digits than its factorization.

21400374 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3566734.

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 21400374 is about 4626.0538258866. The cubic root of 21400374 is about 277.6347272094.

Adding to 21400374 its reverse (47300412), we get a palindrome (68700786).

The spelling of 21400374 in words is "twenty-one million, four hundred thousand, three hundred seventy-four".