1203654661 has 4 divisors (see below), whose sum is σ = 1313077824. Its totient is φ = 1094231500.

The previous prime is 1203654649. The next prime is 1203654677. The reversal of 1203654661 is 1664563021.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1664563021 = 11 ⋅151323911.

It is a cyclic number.

It is not a de Polignac number, because 1203654661 - 2¹³ = 1203646469 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 (1203654691) 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, 54711565 + ... + 54711586.

It is an arithmetic number, because the mean of its divisors is an integer number (328269456).

Almost surely, 2^1203654661 is an apocalyptic number.

1203654661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1203654661 is a deficient number, since it is larger than the sum of its proper divisors (109423163).

1203654661 is a wasteful number, since it uses less digits than its factorization.

1203654661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109423162.

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 1203654661 is about 34693.7265366521. The cubic root of 1203654661 is about 1063.7362694220.

The spelling of 1203654661 in words is "one billion, two hundred three million, six hundred fifty-four thousand, six hundred sixty-one".