20251631 has 2 divisors, whose sum is σ = 20251632. Its totient is φ = 20251630.

The previous prime is 20251619. The next prime is 20251643. The reversal of 20251631 is 13615202.

It is a balanced prime because it is at equal distance from previous prime (20251619) and next prime (20251643).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20251631 is a prime.

It is a super-2 number, since 2×20251631² = 820257116320322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20251601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10125815 + 10125816.

It is an arithmetic number, because the mean of its divisors is an integer number (10125816).

Almost surely, 2^20251631 is an apocalyptic number.

20251631 is a deficient number, since it is larger than the sum of its proper divisors (1).

20251631 is an equidigital number, since it uses as much as digits as its factorization.

20251631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 20251631 is about 4500.1812185733. The cubic root of 20251631 is about 272.5754065646.

Adding to 20251631 its reverse (13615202), we get a palindrome (33866833).

The spelling of 20251631 in words is "twenty million, two hundred fifty-one thousand, six hundred thirty-one".