1662020251 has 4 divisors (see below), whose sum is σ = 1697382432. Its totient is φ = 1626658072.

The previous prime is 1662020233. The next prime is 1662020263. The reversal of 1662020251 is 1520202661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1662020251 is a prime.

It is a super-2 number, since 2×1662020251² = 5524622629468206002, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1662020281) 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, 17681020 + ... + 17681113.

It is an arithmetic number, because the mean of its divisors is an integer number (424345608).

Almost surely, 2^1662020251 is an apocalyptic number.

1662020251 is a deficient number, since it is larger than the sum of its proper divisors (35362181).

1662020251 is an equidigital number, since it uses as much as digits as its factorization.

1662020251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35362180.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 1662020251 is about 40767.8825915696. The cubic root of 1662020251 is about 1184.5282890509.

The spelling of 1662020251 in words is "one billion, six hundred sixty-two million, twenty thousand, two hundred fifty-one".