1211388025 has 9 divisors (see below), whose sum is σ = 1502336973. Its totient is φ = 968971200.

The previous prime is 1211387993. The next prime is 1211388037. The reversal of 1211388025 is 5208831121.

The square root of 1211388025 is 34805.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 30503529 + 1180884496 = 5523^2 + 34364^2 .

It is not a de Polignac number, because 1211388025 - 2⁵ = 1211387993 is a prime.

It is a super-2 number, since 2×1211388025² = 2934921894226801250, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 170545 + ... + 177505.

Almost surely, 2^1211388025 is an apocalyptic number.

1211388025 is the 34805-th square number.

1211388025 is the 17403-rd centered octagonal number.

It is an amenable number.

1211388025 is a deficient number, since it is larger than the sum of its proper divisors (290948948).

1211388025 is an frugal number, since it uses more digits than its factorization.

1211388025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13932 (or 6966 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 31.

The cubic root of 1211388025 is about 1066.0095418187.

The spelling of 1211388025 in words is "one billion, two hundred eleven million, three hundred eighty-eight thousand, twenty-five".