20661142 has 8 divisors (see below), whose sum is σ = 31428432. Its totient is φ = 10185000.

The previous prime is 20661139. The next prime is 20661143. The reversal of 20661142 is 24116602.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20661143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72609 + ... + 72892.

It is an arithmetic number, because the mean of its divisors is an integer number (3928554).

Almost surely, 2^20661142 is an apocalyptic number.

20661142 is a deficient number, since it is larger than the sum of its proper divisors (10767290).

20661142 is a wasteful number, since it uses less digits than its factorization.

20661142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145574.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 20661142 is about 4545.4528927270. The cubic root of 20661142 is about 274.4004215216.

Adding to 20661142 its reverse (24116602), we get a palindrome (44777744).

The spelling of 20661142 in words is "twenty million, six hundred sixty-one thousand, one hundred forty-two".