1001025551 has 8 divisors (see below), whose sum is σ = 1006536960. Its totient is φ = 995524992.

The previous prime is 1001025541. The next prime is 1001025559. The reversal of 1001025551 is 1555201001.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1001025551 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 (1001025559) 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, 238610 + ... + 242768.

It is an arithmetic number, because the mean of its divisors is an integer number (125817120).

Almost surely, 2^1001025551 is an apocalyptic number.

1001025551 is a deficient number, since it is larger than the sum of its proper divisors (5511409).

1001025551 is a wasteful number, since it uses less digits than its factorization.

1001025551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5425.

The product of its (nonzero) digits is 250, while the sum is 20.

The square root of 1001025551 is about 31638.9878314715. The cubic root of 1001025551 is about 1000.3417335382.

Adding to 1001025551 its reverse (1555201001), we get a palindrome (2556226552).

The spelling of 1001025551 in words is "one billion, one million, twenty-five thousand, five hundred fifty-one".