21437494 has 16 divisors (see below), whose sum is σ = 34706448. Its totient is φ = 9872352.

The previous prime is 21437443. The next prime is 21437501. The reversal of 21437494 is 49473412.

It is a happy number.

It is a super-2 number, since 2×21437494² = 919132298000072, 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, 21004 + ... + 22000.

It is an arithmetic number, because the mean of its divisors is an integer number (2169153).

Almost surely, 2^21437494 is an apocalyptic number.

21437494 is a deficient number, since it is larger than the sum of its proper divisors (13268954).

21437494 is a wasteful number, since it uses less digits than its factorization.

21437494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1839.

The product of its digits is 24192, while the sum is 34.

The square root of 21437494 is about 4630.0641464239. The cubic root of 21437494 is about 277.7951581777.

The spelling of 21437494 in words is "twenty-one million, four hundred thirty-seven thousand, four hundred ninety-four".