245251981 has 8 divisors (see below), whose sum is σ = 278018720. Its totient is φ = 214471152.

The previous prime is 245251973. The next prime is 245251991. The reversal of 245251981 is 189152542.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 245251981 - 2³ = 245251973 is a prime.

It is a super-2 number, since 2×245251981² = 120297068368848722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 245251981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (245251991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 496215 + ... + 496708.

It is an arithmetic number, because the mean of its divisors is an integer number (34752340).

Almost surely, 2^245251981 is an apocalyptic number.

It is an amenable number.

245251981 is a deficient number, since it is larger than the sum of its proper divisors (32766739).

245251981 is a wasteful number, since it uses less digits than its factorization.

245251981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 992955.

The product of its digits is 28800, while the sum is 37.

The square root of 245251981 is about 15660.5230117005. The cubic root of 245251981 is about 625.9469217382.

The spelling of 245251981 in words is "two hundred forty-five million, two hundred fifty-one thousand, nine hundred eighty-one".