20401540 has 12 divisors (see below), whose sum is σ = 42843276. Its totient is φ = 8160608.

The previous prime is 20401523. The next prime is 20401553. The reversal of 20401540 is 4510402.

It can be written as a sum of positive squares in 2 ways, for example, as 13089924 + 7311616 = 3618^2 + 2704^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 510019 + ... + 510058.

It is an arithmetic number, because the mean of its divisors is an integer number (3570273).

Almost surely, 2^20401540 is an apocalyptic number.

20401540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20401540 is an abundant number, since it is smaller than the sum of its proper divisors (22441736).

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

20401540 is a wasteful number, since it uses less digits than its factorization.

20401540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1020086 (or 1020084 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 20401540 is about 4516.8063939027. The cubic root of 20401540 is about 273.2463170694.

Adding to 20401540 its reverse (4510402), we get a palindrome (24911942).

The spelling of 20401540 in words is "twenty million, four hundred one thousand, five hundred forty".