1021201251 has 16 divisors (see below), whose sum is σ = 1556725248. Its totient is φ = 583315200.

The previous prime is 1021201243. The next prime is 1021201253. The reversal of 1021201251 is 1521021201.

It is not a de Polignac number, because 1021201251 - 2³ = 1021201243 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1021201251.

It is not an unprimeable number, because it can be changed into a prime (1021201253) 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, 55866 + ... + 71856.

It is an arithmetic number, because the mean of its divisors is an integer number (97295328).

Almost surely, 2^1021201251 is an apocalyptic number.

1021201251 is a deficient number, since it is larger than the sum of its proper divisors (535523997).

1021201251 is a wasteful number, since it uses less digits than its factorization.

1021201251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19042.

The product of its (nonzero) digits is 40, while the sum is 15.

The square root of 1021201251 is about 31956.2396254628. The cubic root of 1021201251 is about 1007.0177200679.

Adding to 1021201251 its reverse (1521021201), we get a palindrome (2542222452).

It can be divided in two parts, 102120 and 1251, that multiplied together give a triangular number (127752120 = T₁₅₉₈₄).

The spelling of 1021201251 in words is "one billion, twenty-one million, two hundred one thousand, two hundred fifty-one".