55015661 has 4 divisors (see below), whose sum is σ = 55262592. Its totient is φ = 54768732.

The previous prime is 55015657. The next prime is 55015663. The reversal of 55015661 is 16651055.

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: 16651055 = 5 ⋅3330211.

It is a cyclic number.

It is not a de Polignac number, because 55015661 - 2² = 55015657 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 (55015663) 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, 123131 + ... + 123576.

It is an arithmetic number, because the mean of its divisors is an integer number (13815648).

Almost surely, 2^55015661 is an apocalyptic number.

It is an amenable number.

55015661 is a deficient number, since it is larger than the sum of its proper divisors (246931).

55015661 is a wasteful number, since it uses less digits than its factorization.

55015661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246930.

The product of its (nonzero) digits is 4500, while the sum is 29.

The square root of 55015661 is about 7417.2542763478. The cubic root of 55015661 is about 380.3313384315.

The spelling of 55015661 in words is "fifty-five million, fifteen thousand, six hundred sixty-one".