251420101 has 4 divisors (see below), whose sum is σ = 255541804. Its totient is φ = 247298400.

The previous prime is 251420087. The next prime is 251420119. The reversal of 251420101 is 101024152.

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

It can be written as a sum of positive squares in 2 ways, for example, as 108139201 + 143280900 = 10399^2 + 11970^2 .

It is a cyclic number.

It is not a de Polignac number, because 251420101 - 2¹⁵ = 251387333 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251420131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2060760 + ... + 2060881.

It is an arithmetic number, because the mean of its divisors is an integer number (63885451).

Almost surely, 2^251420101 is an apocalyptic number.

It is an amenable number.

251420101 is a deficient number, since it is larger than the sum of its proper divisors (4121703).

251420101 is an equidigital number, since it uses as much as digits as its factorization.

251420101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4121702.

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

The square root of 251420101 is about 15856.2322447674. The cubic root of 251420101 is about 631.1510835955.

Adding to 251420101 its reverse (101024152), we get a palindrome (352444253).

The spelling of 251420101 in words is "two hundred fifty-one million, four hundred twenty thousand, one hundred one".