215742 has 16 divisors (see below), whose sum is σ = 442512. Its totient is φ = 70080.

The previous prime is 215737. The next prime is 215753. The reversal of 215742 is 247512.

215742 is nontrivially palindromic in base 5 and base 13.

It is a super-2 number, since 2×215742² = 93089221128, which contains 22 as substring.

It is a plaindrome in base 16.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 193 + ... + 684.

It is an arithmetic number, because the mean of its divisors is an integer number (27657).

2²¹⁵⁷⁴² is an apocalyptic number.

215742 is an abundant number, since it is smaller than the sum of its proper divisors (226770).

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

215742 is a wasteful number, since it uses less digits than its factorization.

215742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 923.

The product of its digits is 560, while the sum is 21.

The square root of 215742 is about 464.4803548052. The cubic root of 215742 is about 59.9761015935.

The spelling of 215742 in words is "two hundred fifteen thousand, seven hundred forty-two".