21347390 has 16 divisors (see below), whose sum is σ = 38953008. Its totient is φ = 8421696.

The previous prime is 21347371. The next prime is 21347419. The reversal of 21347390 is 9374312.

It is a super-2 number, since 2×21347390² = 911422119624200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13892 + ... + 15351.

It is an arithmetic number, because the mean of its divisors is an integer number (2434563).

Almost surely, 2^21347390 is an apocalyptic number.

21347390 is a deficient number, since it is larger than the sum of its proper divisors (17605618).

21347390 is a wasteful number, since it uses less digits than its factorization.

21347390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29323.

The product of its (nonzero) digits is 4536, while the sum is 29.

The square root of 21347390 is about 4620.3235817419. The cubic root of 21347390 is about 277.4054110431.

The spelling of 21347390 in words is "twenty-one million, three hundred forty-seven thousand, three hundred ninety".