20401431 has 16 divisors (see below), whose sum is σ = 27938304. Its totient is φ = 13236224.

The previous prime is 20401429. The next prime is 20401439. The reversal of 20401431 is 13410402.

It is a cyclic number.

It is not a de Polignac number, because 20401431 - 2¹ = 20401429 is a prime.

It is a super-2 number, since 2×20401431² = 832436773695522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20401431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20401439) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35956 + ... + 36518.

It is an arithmetic number, because the mean of its divisors is an integer number (1746144).

Almost surely, 2^20401431 is an apocalyptic number.

20401431 is a deficient number, since it is larger than the sum of its proper divisors (7536873).

20401431 is a wasteful number, since it uses less digits than its factorization.

20401431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 870.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 20401431 is about 4516.7943278392. The cubic root of 20401431 is about 273.2458304411.

Adding to 20401431 its reverse (13410402), we get a palindrome (33811833).

The spelling of 20401431 in words is "twenty million, four hundred one thousand, four hundred thirty-one".