21378650 has 24 divisors (see below), whose sum is σ = 40443840. Its totient is φ = 8405360.

The previous prime is 21378647. The next prime is 21378653. The reversal of 21378650 is 5687312.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21378647) and next prime (21378653).

It is not an unprimeable number, because it can be changed into a prime (21378653) 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, 674 + ... + 6573.

It is an arithmetic number, because the mean of its divisors is an integer number (1685160).

Almost surely, 2^21378650 is an apocalyptic number.

21378650 is a deficient number, since it is larger than the sum of its proper divisors (19065190).

21378650 is a wasteful number, since it uses less digits than its factorization.

21378650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7318 (or 7313 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 21378650 is about 4623.7052241682. The cubic root of 21378650 is about 277.5407509886.

The spelling of 21378650 in words is "twenty-one million, three hundred seventy-eight thousand, six hundred fifty".