20401511 has 12 divisors (see below), whose sum is σ = 22465080. Its totient is φ = 18514080.

The previous prime is 20401501. The next prime is 20401523. The reversal of 20401511 is 11510402.

It is not a de Polignac number, because 20401511 - 2²² = 16207207 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20401501) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9320 + ... + 11298.

It is an arithmetic number, because the mean of its divisors is an integer number (1872090).

Almost surely, 2^20401511 is an apocalyptic number.

20401511 is a deficient number, since it is larger than the sum of its proper divisors (2063569).

20401511 is a wasteful number, since it uses less digits than its factorization.

20401511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2066 (or 2053 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 20401511 is about 4516.8031836687. The cubic root of 20401511 is about 273.2461875997.

Adding to 20401511 its reverse (11510402), we get a palindrome (31911913).

The spelling of 20401511 in words is "twenty million, four hundred one thousand, five hundred eleven".