20511142 has 4 divisors (see below), whose sum is σ = 30766716. Its totient is φ = 10255570.

The previous prime is 20511131. The next prime is 20511143. The reversal of 20511142 is 24111502.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×20511142² = 841413892288328, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20511143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5127784 + ... + 5127787.

It is an arithmetic number, because the mean of its divisors is an integer number (7691679).

Almost surely, 2^20511142 is an apocalyptic number.

20511142 is a deficient number, since it is larger than the sum of its proper divisors (10255574).

20511142 is a wasteful number, since it uses less digits than its factorization.

20511142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10255573.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 20511142 is about 4528.9228299895. The cubic root of 20511142 is about 273.7347585045.

Adding to 20511142 its reverse (24111502), we get a palindrome (44622644).

The spelling of 20511142 in words is "twenty million, five hundred eleven thousand, one hundred forty-two".